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(三)表語從句
表語從句放在連繫動詞之後，充當複合句中的表語。
A 可接表語從句的連繫動詞
可接表語從句的連繫動詞有be, look, seem, sound, appear等。
China is no longer what she used to be.
今日的中國不再是過去的中國了。
The question remains25 whether they will be able to help us.
問題還是他們能否幫我們。
At that time, it seemed as if I couldn't think of the right word anyhow.
當時，我似乎怎麼也想不出一個恰當的字眼來。
B as, as if / though引導的表語從句
He looked just as he had looked ten years before.
他看起來還與十年前一樣。
It sounds as if someone is knocking at the door.
聽起來好像有人在敲門。
C because, why引導的表語從句
That's because he didn't understand me.
那是因為他沒有理解我。 (That's because...強調原因)
That's why he got angry with me.
那正是他對我生氣的原因。 (That's why...強調結果)
what引導的主語從句表示結果或名詞reason作主語時，後面的表語從句表示原因時要用that引導，不宜用because。
The reason why I was sad was that he didn't understand me.
我難過的原因是他沒有理解我。
D 使用虛擬語氣的表語從句
在表示建議、勸告、命令含義的名詞後的表語從句，謂語動詞需用"should+動詞原形"表示，should可省略。常見的詞有：advice, suggestion, order, proposal26, plan, idea等。
My suggestion is that we (should) start early tomorrow.
我的建議是我們明天一早就出發。
His proposal was that they (should) challenge27 the other classes to a friendly competition.
他的提議是挑戰別的班級進行一場友誼競賽。