一、主语从句
1. 由关系代词what、代词whatever或whoever代词引起的主语从句
1) concerned with is the measurement of angles and their relationships to each other．
［A］ Trigonometry is
［B］ That trigonometry is
［C］ What is trigonometry
［D］ What trigonometry is
但what有时在从句中也作定语，如：What little information he collected from it is not enough for us. 他从计算机上收集的那一点点信息不够我们用。
2. 由连词that引起的主语从句，谓语一般是系表结构，在大多数情况下，that从句由it做形式主语
2) has not attained a state of complete coherence is true．
［A］ Cultural anthropology
［B］ That cultural anthropology
［C］ Anthropology that is cultural
［D］ Ｓince cultural anthropology
3) for granted that any new lawn will need to be fertilized．
［A］ Taking it
［B］ Being taken
［C］ Taking
［D］ It should be taken
4) Today ［A］ it is generally recognized as ［B］ the primary function of the Federal Reserve System is to foster the flow of credit and money ［C］ that will eventually facilitate ［D］ a balance in international payments．
3. 由连接代词、连接副词及whether(是否) 引起的主语从句
5) some mammals came to live in the sea is not known．
［A］ That
［B］ Since
［C］ Although
［D］ How
6) made the first United States flag is widely believed．
［A］ When Besty Ross
［B］ That Besty Ross
［C］ Besty Ross
［D］ Whether Besty Ross
4. 由于主语过长，更多的情况下用it代替主语从句，而把that引导的从句放到后边
It is a fact accepted by economists that technological…scarcities.(“it”充当逻辑主语。)
二、宾语从句
1. 由连词that、疑问代词或副词(如how, why和where等)引出的宾语从句
7) Almost all economists agree by trading with one an