Passage One

Among all the animals, the ape is most like human beings. Both people and apes have the similar brain structure, the similar nerve system, and the similar kind of blood. There are four kinds of apes: the chimpanzee (黑猩猩), the orangutan (猩猩), the gorilla (大猩猩), and the gibbon (长臂猿). They live in the deep forests and warm tropical regions of Africa and of Southeast Asia, including Indonesia. All apes are covered with brown, reddish-brown, or black hair everywhere on their bodies except their faces, feet, and hands. Their hands each have four fingers and a thumb that helps them grip things the way our thumbs help us. But they also have a thumb on each foot instead of a big toe. Thus they can hold things with their feet also. Having short, weak legs, apes do not walk on the ground very much. However, their arms are very strong. This enables them to swing from branches and travel very quickly from tree to tree. These animals live in small family groups that move from place to place in search of vegetables and fruits. They also eat eggs, small animals, nuts, and insects. When they are tired, they build nests in the trees. But they rarely sleep there for more than a night or two. Then they move on to look for more food. There are some differences among the following three kinds of apes. The gibbon is never more than three feet high and weighs only about four pounds. The gorilla grows to be six feet tall and weighs up to 600 pounds. The orangutan is smaller than the gorilla. It stands three to five feet tall and weighs up to 200 pounds. Chimpanzees are the smartest of all apes. They can be taught to sit at a table and eat, to dress themselves, and to do things that human children can do.

Among the three kinds of apes,______.