Buck saved Thornton The three men were taking a boat down a fast and rocky river. Thornton was 1 the boat， while Hans and Pete moved along the river bank， holding the boat with a rope. Buck followed them， keeping a worried eye on Thornton. They came to a more 2 part of the river， and the boat started to go too quickly. Hans pulled on the rope to stop it， and pulled too hard. The boat turned over， and Thornton 3 into the water and carried down river towards rocks where no swimmer could live. Buck jumped into the river immediately and swam three hundred meters 4 he reached Thornton. Then he turned， and let Thornton 5 his tail. Buck swam towards the river bank. But they moved 6 . It was hard for them to move. Thornton knew that they would not get to the bank quickly enough， so he let go of Buck， held on to a rock in the middle of the water， and shouted， “Go， Buck， go!”
Modern zoos are very different from zoosthat were built fifty years ago. At that time， zoos were places 21 people could goto see animals from many parts of the world. The animals lived incages that were made 22 concrete withiron bars， cages that were easy to keep clean.
Directions: Read the following three passages. Each passage is followed by several questions or unfinished statements. For each of them there are four choices marked A， B， C and D. Choose the one that fits best according to the information given in the passage you have just read.
