(一)谁杀死了小鸟? 20年前,动物园里,养着一群活泼可爱的小鸟。有一天,其中一只小鸟死了,不明不白的死了。第二天,又有几只小鸟死了,还是不知道为什么死。养小鸟的饲养员心疼极了,却不知道怎么办才好?就这样,在短短的几天里,这群小鸟全都死了。 (A) Who killed the bird? 20 years ago, the zoo, a group of lively and lovely bird. One day, one of the birds died, unidentified dead. The next day, there are a few birds dead, still do not know why die. The breeders of raising birds are distressed, but do not know what to do? In this way, in a matter of days, all these birds are dead.