Collecting stamps as a hobby increasingly popular during the past fifty years. A

Collecting stamps as a hobby___________ increasingly popular during the past fifty years.

       A．becomes              B．became               C．has become         D．had become

试题答案

C

解析:

主语collecting stamps as a hobby被看成是整体，谓语动词用第三人称单数形式。而时间状语during the part fifty years限制了句子用完成时态。

【标签】动名词作主语