第30题: [单项选择]If animal parents were judged by human standards, the cuckoo would be one of nature's more ______ creatures, blithely laying its eggs in the nests of other birds, and leaving the incubating and nurturing to them. A. mettlesome B. industrious C. domestic D. irresponsible 参考答案:D 答案解析:(irresponsible不负责任的)。句意为:如果以人的标准判断动物的父母,布谷鸟是大自然中最不负责任的动物之一,漫不经心地把蛋产在其他的鸟巢当中,把孵化和养育小鸟的事情交给其他的鸟。A.mett