9.The reason why the lake smells terrible is that large quantites of water _____（被污染了）.（pol
问题描述：
9.The reason why the lake smells terrible is that large quantites of water _____（被污染了）.（pol
答
用被动的形式呀
答
have been polluted
quantities of 后无论是可数名词还是不可数名词 谓语都不用单三
答
has been polluted
答
was polluted
has been polluted