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

问题补充：

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

A. when

B. that

C. since

D. while

答案：

A. when

B. that

(答案→)C. since

D. while

解析：假若选B，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. 很显然, 句中的 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。其实，此题应选C，属于“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。