It’s more than half a century my grandfather joined the Party and became a servant to th

It’s more than half a century my grandfather joined the Party and became a servant to the people.
A. since
B. that
C. when
D. while

(答案→)A. sinceB. thatC. whenD. while解析：考查固定句型：“It is＋一段时间＋since 从句”句型，句意为“我爷爷加入党组织成为人民的公仆已有半个多世纪了”。此句的主句谓语也可以用现在完成时态(has been)，但在口语中多用一般现在时代替。这题容易误选B，认为这是强调句型。将此句分析为强调句，那么若将此句还原为非强调句就应该是My grandfather joined the Party and became a servant to the people more than half a century . more than half a century是一段时间，然而它修饰的谓语动词 joined…became 却是两个终止性动词，这显然不合适。所以选A。

好好学习下