China is no longer what she used to be.
The question remains whether they will be able to help us.
At that time，it seemed as if I couldn't think of the right word.
2. 从属连词whether，as，as if / though引导的表语从句。
He looked just as he had looked ten years before.
It sounds as if someone is knocking at the door.
That's because he didn't understand me.
That's why he got angry with me.
The reason why I was sad was that he didn't understand me.
The problem is who we can get to replace her.
The question is how he did it.
That was what she did this morning on reaching the attic.
The trouble is that I have lost his address.
My suggestion is that we （should） start early tomorrow.
It was because he didn't pass the exam.
It seems（that）he was late for the train.
It appears that she was wrong.
It seems to me that we should answer for this.
It appears to her that he wants to teach us all he has.
My question is who left
What I wonder is when he left.
That's what he wants.
This is where they once lived.
That is why he didn't come here. 这就是他为何没到这儿来的原因。
My question is whether he left（or not）。 我的问题是他是否离开了。
The fact is that he left. 事实是他离开了。
The truth is（that）I didn't go there. 事实是我没去那儿。
4）because，as，as if，as though
It's just because he doesn't know her. 这是仅仅因为他不认识她。
Things are not always as they seem to be. 事物并不总是如其表象。
He looks as if he's tired. 他好像累了。