People find that it difficult to study AB (一种动物），a species native to Amason water area, mainly (because it feeds and nests)......
another choice is: because they feed and nest 作者: rabbitbug 时间: 2003-12-26 18:59
MM, 能不能把题目补充完整? 尤其是AB的那种动物的形式, 原文的单复数取决于这道题的答案, 单凭后面的同位语a species无法判断出AB的真实单复数, 也就无从作答.