名词性从句
1． After working on the maths problem for hours，he found________ he thought was the key to it.
A．what B．that
C．where D．which
解析：what引导的名词性从句作found的宾语从句的主语，而且what在宾语从句中作主语。he thought 为插入语。
答案：A
2．Sometimes advertisements make ________ possible for companies to sell the customers ________ money can not buy.
A．/；that B．it；what
C．that；which D．it；whose
解析：句意为：有时广告让公司把用钱买不到的东西卖给顾客变得可能。it是形式宾语，真正的宾语是不定式短语。what 引导的是宾语从句，并在宾语从句中作宾语。
答案：B
3．So quickly are science and technology advancing ________ is a possibility today may be a reality tomorrow.
A．which B．what
C．that which D．that what
解析：句意：科技发展如此迅速以至于今天的可能也许会成为明天的现实。本句是“so ...that ...”句型，表示“如此……以至于……”，结果状语从句中又包含了一个主语从句，what在该主语从句中作主语。
答案：D
4．She is very dear to us.We have been prepared to do________ it takes to save her life.
A．whichever B．however
