How time flies! Ten years really a short time.A. wasB. wereC. isD. are

问题补充：

How time flies! Ten years really a short time.

A. was

B. were

C. is

D. are

答案：

A. was

B. were

(答案→)C. is

D. are

解析：句意:时间过得真快！十年这是很短的一段时间。这句话的主语是ten years，十年，表示时间、距离、金钱、重量等的复数名词做主语时，经常把他们看做是一个整体，谓语动词仍用单数形式，故排除B和D；根据句中的flies可知，这里用的是一般现在时，故选C。