A few cups of green tea each day may help pr heart disease,Greek researchers said on Wednesday.A study published in the European Journal of Cardiovascular (心血管的) Prion showed further evidence of the potential health benefits from tea already linked to a reduced risk of a range of cancers and other conditions. The study showed that green tea improves blood flow and the ability of arteries (动脉) to relax,said Charalambos Vlachopoulos,an expert at the Athens Medical School in Greecewho worked on the study. Other studies have shown that black tea also has benefits for cardiovascular health. The Greek team said they believed green tea might be even better because it had higherquantities of beneficial substances called flavonoids (类黄酮)-some of which are lost in theoxidation (氧化) process that black tea undergoes. Flavonoids are also found in cocoa,tomatoes and gs."A couple of cups a day would probably be good for people," Vlachopoulos said."This is the first study to show theseeffects for green tea." The researchers gave 14 healthy volunteers either green tea,coffee or hot water and thenmeasured the function of endothelial cells (内皮细胞)．These cells help relax arteries andease blood flow."What is important is these effects are evident within 30 minutes,"Vlachopoulos said. The measurements taken 30,90 and 120 minutes following consumption showed an almost immediate benefit among people who had drunk green tea,he said.While the researcherslooked only at a short-term effect,Vlachopoulos said the team's studies suggest the protectionis long-lasting. "Green tea is consumed less in the Western world than black tea,but it could be morebeneficial,"he said. 1．What would be the best title for the passage?_____ A．B enefits from black teaB．Different kinds of teaC．Green tea protects against heart diseaseD．Green tea reduces the risk of cancer 2．According to the study,green tea can do the following EXCEPT________. A．improve blood flowB．benefit cardiovascular healthC．help relax arteriesD．increase the oxidation rate of flavonoids 3．Which of the following statements is TRUE?______ A．Green tea is better than black tea because it has been processed.B．Green tea contains more flavonoids than black tea.C．Vlachopoulos's study is based on many years' research.D．Vlachopoulos's study is the first to show green tea's benefits. 4．We can learn from the passage that________. A．14 volunteers with heart disease joined in the experimentB．it takes an hour for green tea to take effectC．green tea has a long－lasting effect according to VlachopoulosD．Westerners prefer green tea to black tea 5．Which one of the following factors is NOT related with the research procedure?______ A．The volunteers.B．The drinks.C．Blood samples.D．Objects for time－measuring