The study of animals in parks and in the wild has given a deeper knowledge of their habits: the result has been a great (36) in the way they are treated, housed and bred. For example, most animals are now kept in (37) because it has been discovered that, like people, they are happier in the company of their fellows. It has been recognised also that as they are complicated creatures, keeping them happy enough to (38) and multiply in captivity (囚禁) is a complicated operation. Zoo directors, keepers, and veterinarians (兽 医) have (39) stories to tell about the problems that have to be (40) before romance (浪漫故事) can bloom in the zoo. Some animals will not breed without a special diet; others must feel far from human separation, and others need large spaces for their courtship dances. Some males insist on (41) to win their mate. Then there is the question of personal (42) , as was demonstrated by the female panda of the London Zoo, and the male panda in Moscow. After long and difficult discussions between representatives of the two countries involved, it was (43) decided that two bears would take turns flying to each other’s residence in England and in Russia. The humans went to considerable expenses and (44) to bring the bears together, but they could not get them interested in each other. It seems that all pandas are hard to please; the Washington Zoo has been (45) with its own pair for years, without much result. A. countless E. eventually I. recognised M. unwillingly B. struggling F. scarce J. easy N. preferences C. fighting G. trouble R. flourish O. succeed D. solved H. groups L. improvement