Thanks to the old man’s hard work a lot of has been covered with green trees.A. the hill

问题补充：

Thanks to the old man’s hard work, a lot of has been covered with green trees.

A. the hills

B. hills

C. the hill

D. hill

答案：

A. the hills

B. hills

(答案→)C. the hill

D. hill

解析：解此题的关键词是谓语动词has，可见主语是单数意义的名词，可以先排除A、B，其次要注意该名词前面有a lot of来修饰，此时的a lot of不是指“许多”，而是相当于a large part of，后跟表示特定意义的名词the hill，意思是“这座山的多数地方”