Question

We know that about seventy percent _____ the earth _____ covered by water.

A．/; is	B．of; are
C．of; is	D．about; are

Answer 1

C

试题分析：句意：我们都知道70%的土地都被水覆盖。百分数+名词做主语，谓语动词的选择要根据这个名词而定。本题中earth是不可数名词，因此谓语动词要用单数。故选C。