【问】 The Social Security Retirement Program is made up of two trust funds，____could gopenniless by next year.

A. the larger one B. the larger of which

C. the largest one D. the largest of which(攻读硕士学位研究生入学考试英语试题，97)

虽然我从参考书上得知，答案为B(the larger of which)。但是，我对于…of which的用法仍是昏昏然。

【答】 which引导定语从句并在定语从句中充当主语或宾语的用法，是大家所熟悉的。但是，假如which在定语从句中不充当主语或宾语，而是充当定语来表示领属关系，那怎么办呢?这时候就需要使用of which这个短语。在上面的句子里，which的先行词是two trust funds

(两项信托资金)，of which作the larger的定语。请考察类似的实例：

1. the investigation the results of which will soon be published... (CGEL)

结果不久即将公布的那项调查……

2. The house the roof of which was damaged has now been repaired. (CGEL)

房顶损坏的那所房子现在已修好了。

3. There are two left，one of which is almost finished and the other of which is not quite.(LDCE)

剩下两件事，一件几乎干完了，另一件还得干。