有這樣一道題：

Mrs Brown was much disappointed to see the washing machine she had had _________ went wrong again.

A. it B. it repaired C. repaired D. to be repaired

這是一道上海高考英語題，答案選C，許多考生因不能正確分析句子結構，不知如何下筆。現分析如下：句中to see 后的基本結構是：the washing machine went wrong again.(洗衣機又出毛病了)，其中 (that) she had had repaired 套用的句型是“have + 名詞或代詞 + 過去分詞”，即 have the washing machine repaired;另外，從時間上看，“請人修洗衣機”應在“出故障”之前，故 have the washing machine repaired 用了過去完成時態，即用 had had the washing machine repaired;從修飾角度看，題目中she had had repaired 為修飾名詞 the washing machine 的定語從句(意為“她曾請人修理過的洗衣機”)，引導該定語從句的關系代詞為 that，因其用作賓語被省略，也正因為如此，題目中的 she had had repaired 的第二個had 后既不能用 the washing machine 或 it，這也就是為什么不能選B的原因。如果有的同學還明白，我們可以從反面來分析一下：假若選B，則有 (that) she had had it repaired，而它作為修飾 the washing machine 的定語從句是有問題的，為什么有問題呢?那是因為 she had had it repaired 這個句子的結構(或成分)是完整的，它有主語、有謂語、有賓語，這樣一來，引導這個定語從句的關系代詞 that 就沒有著落了，因為關系代詞 that 要么作主語(不可省略)，要么作賓語(可以省略)，而 she had had it repaired 這個定語從句既不缺主語，也不缺賓語，所以錯了。假若去掉其中的 it，即改選C，則對了，因為這樣一來，that 可用作動詞 repaired 的賓語。現在我們將此題改編一下，將其改為：

Mrs Brown was much disappointed to see the washing machine she had _________ went wrong again.

A. it B. it repaired C. repaired D. to be repaired

答案應選哪個呢?選B還是C?仍然要選C，但是意思變了，即“她自己修理過的洗衣機又出故障了”，因為此時修飾 the washing machine 的定語從句變成了 she had repaired。不能選B，道理同上。

請比較下面一題：

A computer does only what thinking people _________.

A. have it do B. have it done C. have done it D. having it done

答案選A，選項中的 it 指的是 the computer，而不是指 the work 之類的。其中的 what 用作動詞 do 的賓語。句意為“人們要計算機做什么，它就做什么”。