Section_ⅢGrammar-_名词性从句(主语从句、宾语从句和表语从句)

　　语法图解

　　探究发现

　　①Exactly when the first people arrived in what we now know as California, no one really knows.

　　②However, it is likely that Native Americans were living in California at least fifteen thousand years ago.

　　③Scientists believe that these settlers crossed the Bering Strait in the Arctic to America by means of a land bridge which existed in prehistoric times.

　　④That is why today over 40% of Californians speak Spanish as a first or second language.

　　⑤It is believed that before long the mix of nationalities will be so great that there will be no distinct major racial or cultural groups, but simply a mixture of many races and cultures.

　　[我的发现]

　　(1)以上各句皆为主从复合句，句中用了相当于名词作用的从句(即名词性从句)在句中充当成分。

　　(2)名词性从句在句中可作介词的宾语(句①)，动词的宾语(句③)。

　　(3)名词性从句在句中可作主语，且可用it作形式主语，真正的主语从句置于句末(句②、⑤)。

　　(4)名词性从句在句中可作表语(句④)。