问题
选择题
---Did you hear that water in Tai Lake smelled terrible?
--- Yes.It ___________ because of people and factories.
A. polluted B. was polluted C.has polluted
答案
答案：B
题目分析： be+动词的过去分词构成被动语态，其过去时为were/was+动词的过去分词。句意：你听说太湖的水闻起来非常糟糕了吗？是的，因为水被人类和工厂污染了。问句是过去时，主语又是it，故选B。