名詞性從句：從句在主句中的成分相當(dāng)于名詞，又被稱為名詞從句；
根據(jù)從句在主句中所做的成分，名詞性從句可以分為以下4種：
例如：
（1）That the seas are being overfished has been known for years.
? ? ? ?海洋正在被人們過渡捕撈，許多年來這已是盡人皆知的事情了。
（2）I have learned that love, not time, heals all wounds.
? ? ? ?我明白了是愛，而不是時(shí)間能治愈一切創(chuàng)傷。
（3）The reason for my return is that I left my keys behind.
? ? ? ?我又回來，是因?yàn)槲彝鼛ц€匙了。
（4）An idea came to her that she might do the experiment in another way.
? ? ? ?她突然想到，她可以換個(gè)方法做實(shí)驗(yàn)。