Question

【题目】We can not figure out quite a number of insects, birds, and animals are dying out.

that

as

why

when

Answer 1

【答案】C

【解析】句意：我们找不出大量昆虫、鸟和动物逐渐殆灭绝的原因。宾语从句中缺原因状语，故用why引导。