Why does the lake smell terrible?Because large quantities of water( )a have polluted b is being
问题描述：
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 选什么?
答
选D,主语是quantities,复数.所以用have
water 和 polluted是被动关系,所以用BE动词.
望采纳,希望能帮到你