two thirds is/are

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(即用于复数可数名词之前)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 area is under water.

2. 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 $\$frac{\text{three-fourths}}{\text{A}} of $\$frac{\text{the earth's}}{\text{B}} surface $\$frac{\text{are}}{\text{C}} covered $\$frac{\text{with}}{\text{D}} water.