— Why does the lake smell terrible?
— Because large quantities of water .
A. have polluted
B. is being polluted
C. has been polluted
D. have been polluted
网友回答
A. have polluted
B. is being polluted
C. has been polluted
(答案→)D. have been polluted
解析：考察主谓一致。large quantities of许多，大量；该短语既可以修饰可数名词，也可以修饰不可数名词；做主语时，谓语动词使用复数形式。本句的主语是large quantities of water，故后面的谓语动词使用复数形式。句意：大量的水都被污染了。故D正确。