【问】 “How is the progress?”

“Two-thirds of the work____finished.”

A. are B. is C. to be D. will(TOEFL)

这里为什么只能选B，而不能选A?

【答】 表示分数的短语，不论分子是1，还是大于1，当用于表示量(即用于不可数名词之前)时，谓语动词要用单数;当用于表示数目(即用于可数名词之前)时，谓语动词要用复数，即这里起作用的是概念一致的原则：

1. Two thirds of the land was uncultivated.

2. Two thirds of the area is under water.

3. Two thirds of the apples were bad.

有了上面的知识，便可以很容易解答下列试题：

Approximately three-fourths of the earth’s surface are covered with water.