Mr Chen told us that three fourths of the earth covered with water.A. wereB. isC. wasD. ar

问题补充：

Mr Chen told us that three fourths of the earth covered with water.

A. were

B. is

C. was

D. are

答案：

A. were

(答案→)B. is

C. was

D. are

解析：句意：陈老师告诉我们地球的四分之三都被水覆盖着。宾语从句中的事实为客观真理，所以时态用一般现在时，the earth做主语，后面的谓语动词用单数形式，故选B。