------ Why does the lake smell terrible?
------ Because large quantities of water .
A. have been polluted
B. has polluted
C. have polluted
D. has been polluted
网友回答
(答案→)A. have been polluted
B. has polluted
C. have polluted
D. has been polluted
解析：考查主谓一致与语态。large quantities of +名词作主语，位于动词用复数；water与pollute构成被动的关系。所以选择A。