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Many animals test their legs and totter forth only hours after they are born, but humans need a year before they take their first, hesitant steps. Is something fundamentally different going on in human babies Maybe not. (46) A new study shows that the time it takes for humans and all other mammals to start walking fits closely with the size of their brains.
(47) In past studies to develop a new animal model for the brain s that support motor development, neurophysiologist Martin Garwicz discovered that the schedules by which ferrets and rats acquire various motor skills, such as crawling and walking, are strikingly similar to each other; the progress simply happens faster for rats. That made them wonder how similar the timing of motor development might be among mammals in general.
(48) They compared the time between conception and walking in 24 species and looked at how well this duration correlated with a range of variables, including gestation time, body mass, and brain mass. As they report in this week’s issue of PNAS, brain mass accounts for the vast majority (94%) of the variance in walking time between species.
Species with larger brains, such as humans, tend to take longer to learn to walk. (49) Strikingly, a model based on brain mass and walking time in the other 23 species almost perfectly predicts when humans begin to walk. "We’ve always considered humans the exception," Garwicz says, "But in fact, we start walking at exactly the time that would be expected from all other walking mammals. "
Two other variables—gestation time and brain mass at birth—also correlate nicely with age of walking for most animals, but not for humans. That makes sense, the researchers say: Humans spend an unusually small portion of their development—and build an unusually small fraction of their brain mass—in the womb. (50) The model is able to accommodate this quirk of human development because it uses the time it takes babies to learn to walk from conception, not birth. (At the other extreme, animals such as horses, who have a long gestation and then walk almost immediately after they are born, also fit the model.)
Barbara Finlay, a neuroscientist at Cornell University, says the findings support the existence of a kind of a development "clock" for mammals. In her own work, Finlay has found that various mammals have similar timetables for brain development before birth. But she had imagined that a postnatal milestone such as walking would be more idiosyncratic. "I was surprised," she says. "I thought the clock would start to fracture. " It will be interesting, she says, to see if the clock will keep time for later milestones, such as s related to reproduction.
(48) They compared the time between conception and walking in 24 species and looked at how well this duration correlated with a range of variables, including gestation time, body mass, and brain mass.
Many animals test their legs and totter forth only hours after they are born, but humans need a year before they take their first, hesitant steps. Is something fundamentally different going on in human babies Maybe not. (46) A new study shows that the time it takes for humans and all other mammals to start walking fits closely with the size of their brains.
(47) In past studies to develop a new animal model for the brain s that support motor development, neurophysiologist Martin Garwicz discovered that the schedules by which ferrets and rats acquire various motor skills, such as crawling and walking, are strikingly similar to each other; the progress simply happens faster for rats. That made them wonder how similar the timing of motor development might be among mammals in general.
(48) They compared the time between conception and walking in 24 species and looked at how well this duration correlated with a range of variables, including gestation time, body mass, and brain mass. As they report in this week’s issue of PNAS, brain mass accounts for the vast majority (94%) of the variance in walking time between species.
Species with larger brains, such as humans, tend to take longer to learn to walk. (49) Strikingly, a model based on brain mass and walking time in the other 23 species almost perfectly predicts when humans begin to walk. "We’ve always considered humans the exception," Garwicz says, "But in fact, we start walking at exactly the time that would be expected from all other walking mammals. "
Two other variables—gestation time and brain mass at birth—also correlate nicely with age of walking for most animals, but not for humans. That makes sense, the researchers say: Humans spend an unusually small portion of their development—and build an unusually small fraction of their brain mass—in the womb. (50) The model is able to accommodate this quirk of human development because it uses the time it takes babies to learn to walk from conception, not birth. (At the other extreme, animals such as horses, who have a long gestation and then walk almost immediately after they are born, also fit the model.)
Barbara Finlay, a neuroscientist at Cornell University, says the findings support the existence of a kind of a development "clock" for mammals. In her own work, Finlay has found that various mammals have similar timetables for brain development before birth. But she had imagined that a postnatal milestone such as walking would be more idiosyncratic. "I was surprised," she says. "I thought the clock would start to fracture. " It will be interesting, she says, to see if the clock will keep time for later milestones, such as s related to reproduction.
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【单选题】10（） A.accumulates B.amasses C.collects D.gathers
A.
Current gym dogma holds that to build muscle size you need to lift heavy weights. (1) , a new study (2) at McMaster University has shown that a similar degree of muscle building can be achieved by using lighter weights. The secret is to pump air (3) you reach muscle fatigue.
B.
The (4) are published in PLoS ONE.
C.
" (5) grunting and straining to lift heavy weights, you can (6) something much lighter but you have to lift it until you can’t lift it (7) ," says Stuart Phillips, associate professor of kinesiology at McMaster University. "We’re convinced that (8) muscle means (9) your muscle to make new muscle proteins, a process in the body that over time (10) into bigger muscles. "
D.
Phillips praised lead author and senior Ph.D. student Nicholas Burd for masterminding the project that showed it’s really not the weight that you lift but the fact that you get muscular fatigue that’s the (11) point in building muscle. The study used light weights that (12) a percentage of what the (13) could lift. The heavier weights were set (14) 90% of a person’s best lift and the light weights at a mere 30%o of what people could lift. "It’s a very light weight," says Phillips noting that the 80% 90% (15) is usually something people can lift from 5～10 times before fatigue sets in. At 30%, Burd reported that subjects could lift that weight at least 24 times (16) they felt fatigue.
E.
"We’re (17) to see where this new paradigm will lead," says Phillips, adding that these new data have (18) significance for gym enthusiasts but more importantly for people with compromised skeletal muscle mass, (19) the elderly, patients with cancer, or those who are (20) from trauma, surgery or even stroke.
【单选题】What’s the meaning of the word "beeline" in Paragraph 5（） A. Winding road. B. Are line. C. Zigzag. D. Straight line.
A.
Men are generally better than women on tests of spatial ability, such as mentally rotating an object through three dimensions or finding their way around in a new environment. But a new study suggests that under some circumstances a woman’s way of navigating is probably more efficient.
B.
Luis Pacheco-Cobos of the National Autonomous University of Mexico and his colleagues discovered this by following mushroom gatherers from a village in the state of Tlaxcala for two rainy seasons. Two researchers, each fitted with GPS navigation devices and heart-rate monitors, followed different gatherers on different days. They recorded the weight of the mushrooms each gatherer collected and where they visited. The GPS data allowed a map to be made of the routes taken and the heart-rate measurements provided an estimate of the amount of energy expended during their travels.
C.
The results, to be published in Evolution and Human Behavior, show that the men and women collected on average about the same weight of mushrooms. But the men travelled farther, climbed higher and used a lot more energy—70% more titan the women. The men did not move any faster, but they searched for spots with lots of mushrooms. The women made many more stops, apparently satisfied with, or perhaps belier at finding, patches of fewer mushrooms.
D.
Previous work has shown that men tend to navigate by creating mental maps of a territory and then imagining their position on the maps. Women are more likely to remember their mutes using landmarks. The study lends support to the idea that male and female navigational skills were honed differently by evolution for different tasks. Modern-day hunter-gatherers divide labor, so that men tend to do more hunting and women more gathering. It seems likely that early humans did much the same thing.
E.
The theory is that the male strategy is the most useful for hunting prey; chasing an antelope, say, would mean running a long way over a winding mute. But having killed his prey, the hunter would want to make a beeline for home rather than retrace his steps exactly. Women, by contrast, would be better off remembering landmarks and retracing the paths to the most productive patches of plants.
F.
The research suggests that in certain circumstances women are better at navigating than men, which might lend some comfort to a man desperately searching for an item in a supermarket while his exasperated wife methodically moves around the aisles filling the shopping trolley. He is simply not cut out for the job, evolutionarily speaking.
【单选题】2007年7月，我国的网民数量为多少人（） A．2.1亿 B．2.05亿 C．1.82亿 D．1.62亿
A.
CNNIC于2008年7月发布的《第22次中国互联网络发展状况统计报告》显示，我国网民数达2.53亿，超美国居世界首位。尽管如此，我国互联网普及率只有19.1%，仍然低于21.1%的全球平均水平。与上年同期相比，我国网民人数增加了9100万，是历年来增长最快的一年，同比增长56.2%。仅2008年上半年，我国网民数净增量就达4300万。统计表明，我国网站数量持续增长，截至2008年7月共有网站191.9万个，同比增长率为46.39%；其中CN域名下的网站数为136.9万个。
B.
【单选题】甲公司于2004年注册了“柠檬”商标，该商标被核准使用于电冰箱上。为获取收益，甲公司许可乙公司在其生产的电冰箱上使用“柠檬”商标。为了有效保护该商标，甲公司又申请注册了“白柠檬”、“青柠檬”、“黄柠檬”3件商标。后来，甲公司的电冰箱产品出现了粗制滥造、以次充好、欺骗消费者的现象。丙公司于2008年注册了“小柠檬”商标，也使用于电冰箱上。2010年，甲公司发现丙公司注册并使用“小柠檬”商标的行为。 ...
A.
可以撤销其注册商标
B.
不可以撤销其注册商标
C.
可以责令其停止经营
D.
可以对其予以警告
【单选题】11（） A.certain B.critical C.whole D.plus
A.
Current gym dogma holds that to build muscle size you need to lift heavy weights. (1) , a new study (2) at McMaster University has shown that a similar degree of muscle building can be achieved by using lighter weights. The secret is to pump air (3) you reach muscle fatigue.
B.
The (4) are published in PLoS ONE.
C.
" (5) grunting and straining to lift heavy weights, you can (6) something much lighter but you have to lift it until you can’t lift it (7) ," says Stuart Phillips, associate professor of kinesiology at McMaster University. "We’re convinced that (8) muscle means (9) your muscle to make new muscle proteins, a process in the body that over time (10) into bigger muscles. "
D.
Phillips praised lead author and senior Ph.D. student Nicholas Burd for masterminding the project that showed it’s really not the weight that you lift but the fact that you get muscular fatigue that’s the (11) point in building muscle. The study used light weights that (12) a percentage of what the (13) could lift. The heavier weights were set (14) 90% of a person’s best lift and the light weights at a mere 30%o of what people could lift. "It’s a very light weight," says Phillips noting that the 80% 90% (15) is usually something people can lift from 5～10 times before fatigue sets in. At 30%, Burd reported that subjects could lift that weight at least 24 times (16) they felt fatigue.
E.
"We’re (17) to see where this new paradigm will lead," says Phillips, adding that these new data have (18) significance for gym enthusiasts but more importantly for people with compromised skeletal muscle mass, (19) the elderly, patients with cancer, or those who are (20) from trauma, surgery or even stroke.
【单选题】Hostility to Gypsies has existed almost from the time they first appeared in Europe in the 14th century. The origins of the Gypsies, with little written history, were shrouded in mystery. What is know...
A.
they themselves refuse to be counted
B.
those who control a country are eager to despise their image, seeking to avoid bureaucracies
C.
those who control a country refuse to count them since they are ugly
D.
both A and B
相关题目：
【单选题】10（） A.accumulates B.amasses C.collects D.gathers
A.
Current gym dogma holds that to build muscle size you need to lift heavy weights. (1) , a new study (2) at McMaster University has shown that a similar degree of muscle building can be achieved by using lighter weights. The secret is to pump air (3) you reach muscle fatigue.
B.
The (4) are published in PLoS ONE.
C.
" (5) grunting and straining to lift heavy weights, you can (6) something much lighter but you have to lift it until you can’t lift it (7) ," says Stuart Phillips, associate professor of kinesiology at McMaster University. "We’re convinced that (8) muscle means (9) your muscle to make new muscle proteins, a process in the body that over time (10) into bigger muscles. "
D.
Phillips praised lead author and senior Ph.D. student Nicholas Burd for masterminding the project that showed it’s really not the weight that you lift but the fact that you get muscular fatigue that’s the (11) point in building muscle. The study used light weights that (12) a percentage of what the (13) could lift. The heavier weights were set (14) 90% of a person’s best lift and the light weights at a mere 30%o of what people could lift. "It’s a very light weight," says Phillips noting that the 80% 90% (15) is usually something people can lift from 5～10 times before fatigue sets in. At 30%, Burd reported that subjects could lift that weight at least 24 times (16) they felt fatigue.
E.
"We’re (17) to see where this new paradigm will lead," says Phillips, adding that these new data have (18) significance for gym enthusiasts but more importantly for people with compromised skeletal muscle mass, (19) the elderly, patients with cancer, or those who are (20) from trauma, surgery or even stroke.
【单选题】What’s the meaning of the word "beeline" in Paragraph 5（） A. Winding road. B. Are line. C. Zigzag. D. Straight line.
A.
Men are generally better than women on tests of spatial ability, such as mentally rotating an object through three dimensions or finding their way around in a new environment. But a new study suggests that under some circumstances a woman’s way of navigating is probably more efficient.
B.
Luis Pacheco-Cobos of the National Autonomous University of Mexico and his colleagues discovered this by following mushroom gatherers from a village in the state of Tlaxcala for two rainy seasons. Two researchers, each fitted with GPS navigation devices and heart-rate monitors, followed different gatherers on different days. They recorded the weight of the mushrooms each gatherer collected and where they visited. The GPS data allowed a map to be made of the routes taken and the heart-rate measurements provided an estimate of the amount of energy expended during their travels.
C.
The results, to be published in Evolution and Human Behavior, show that the men and women collected on average about the same weight of mushrooms. But the men travelled farther, climbed higher and used a lot more energy—70% more titan the women. The men did not move any faster, but they searched for spots with lots of mushrooms. The women made many more stops, apparently satisfied with, or perhaps belier at finding, patches of fewer mushrooms.
D.
Previous work has shown that men tend to navigate by creating mental maps of a territory and then imagining their position on the maps. Women are more likely to remember their mutes using landmarks. The study lends support to the idea that male and female navigational skills were honed differently by evolution for different tasks. Modern-day hunter-gatherers divide labor, so that men tend to do more hunting and women more gathering. It seems likely that early humans did much the same thing.
E.
The theory is that the male strategy is the most useful for hunting prey; chasing an antelope, say, would mean running a long way over a winding mute. But having killed his prey, the hunter would want to make a beeline for home rather than retrace his steps exactly. Women, by contrast, would be better off remembering landmarks and retracing the paths to the most productive patches of plants.
F.
The research suggests that in certain circumstances women are better at navigating than men, which might lend some comfort to a man desperately searching for an item in a supermarket while his exasperated wife methodically moves around the aisles filling the shopping trolley. He is simply not cut out for the job, evolutionarily speaking.
【单选题】2007年7月，我国的网民数量为多少人（） A．2.1亿 B．2.05亿 C．1.82亿 D．1.62亿
A.
CNNIC于2008年7月发布的《第22次中国互联网络发展状况统计报告》显示，我国网民数达2.53亿，超美国居世界首位。尽管如此，我国互联网普及率只有19.1%，仍然低于21.1%的全球平均水平。与上年同期相比，我国网民人数增加了9100万，是历年来增长最快的一年，同比增长56.2%。仅2008年上半年，我国网民数净增量就达4300万。统计表明，我国网站数量持续增长，截至2008年7月共有网站191.9万个，同比增长率为46.39%；其中CN域名下的网站数为136.9万个。
B.
【单选题】甲公司于2004年注册了“柠檬”商标，该商标被核准使用于电冰箱上。为获取收益，甲公司许可乙公司在其生产的电冰箱上使用“柠檬”商标。为了有效保护该商标，甲公司又申请注册了“白柠檬”、“青柠檬”、“黄柠檬”3件商标。后来，甲公司的电冰箱产品出现了粗制滥造、以次充好、欺骗消费者的现象。丙公司于2008年注册了“小柠檬”商标，也使用于电冰箱上。2010年，甲公司发现丙公司注册并使用“小柠檬”商标的行为。 ...
A.
可以撤销其注册商标
B.
不可以撤销其注册商标
C.
可以责令其停止经营
D.
可以对其予以警告
【单选题】11（） A.certain B.critical C.whole D.plus
A.
Current gym dogma holds that to build muscle size you need to lift heavy weights. (1) , a new study (2) at McMaster University has shown that a similar degree of muscle building can be achieved by using lighter weights. The secret is to pump air (3) you reach muscle fatigue.
B.
The (4) are published in PLoS ONE.
C.
" (5) grunting and straining to lift heavy weights, you can (6) something much lighter but you have to lift it until you can’t lift it (7) ," says Stuart Phillips, associate professor of kinesiology at McMaster University. "We’re convinced that (8) muscle means (9) your muscle to make new muscle proteins, a process in the body that over time (10) into bigger muscles. "
D.
Phillips praised lead author and senior Ph.D. student Nicholas Burd for masterminding the project that showed it’s really not the weight that you lift but the fact that you get muscular fatigue that’s the (11) point in building muscle. The study used light weights that (12) a percentage of what the (13) could lift. The heavier weights were set (14) 90% of a person’s best lift and the light weights at a mere 30%o of what people could lift. "It’s a very light weight," says Phillips noting that the 80% 90% (15) is usually something people can lift from 5～10 times before fatigue sets in. At 30%, Burd reported that subjects could lift that weight at least 24 times (16) they felt fatigue.
E.
"We’re (17) to see where this new paradigm will lead," says Phillips, adding that these new data have (18) significance for gym enthusiasts but more importantly for people with compromised skeletal muscle mass, (19) the elderly, patients with cancer, or those who are (20) from trauma, surgery or even stroke.
【单选题】Hostility to Gypsies has existed almost from the time they first appeared in Europe in the 14th century. The origins of the Gypsies, with little written history, were shrouded in mystery. What is know...
A.
they themselves refuse to be counted
B.
those who control a country are eager to despise their image, seeking to avoid bureaucracies
C.
those who control a country refuse to count them since they are ugly
D.
both A and B
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