模块四unit5Workbook listening & reading(17)

S1: Yes, that’s true, but they needn’t keep the animals in the zoos for their whole lives, They ought to return the animals to the wild. I read that some animals in zoos have difficulty having babies. Some animals cannot continue their family line because of the environment of zoos. S2: But I read that many zoos will not buy wild animals any more- they will only buy animals born in other zoos, so some zoo animals must be able to have babies.