If you are translate English into Chinese, then read this. If not, sorry, this might be useless.

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adj 得

2. 这个考试难得没有人考完了。公交车快得大家早到了。

This test is so hard, that no one finish. Bus is so fast, that everyone arrived early.

As a Chinese, I'd like to translate 'This test is so hard, that no one finish'  as ‘考试太难了，没人写得完’. Because in chinese '考完' just means the test is over (or the time for you answering questions ends) regardless of whether you answer all the question or not.

So if your 'finish' means finish all the questions, please use '写完(this means that you have writen everything you know )'. It's better.

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刚 verb, 就

3. 我刚到了，他就出去。 我刚看到，就忘了。

I just arrived, he just went out. I just saw it, and forgot.

I just arrived, he just went out. —— 我刚到，他就出去了。

You should just say this like what you do in the second sentence.

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adj 得像

4. 她漂亮得像主演. 她小得孩子。

She is pretty as a movie star. She is small like a child.

'Movie star' means 电影明星，while '主演'  means those who are playing as the protagonists.

In the second sentence, you just miss a '像' after the '得'.

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I'm just new here, if there are anything not correct, tell me please.

1. 今天，我去上课了，还读了一本书。后来，我吃了饭，还喝了水。In the ordinary chinese, “了” dont has mean.But when we finshed one thing, we offten add “了”.

1. "我吃饭，又喝水" is wrong. “又” means do something again. So you can say "我不但吃了饭，还喝了水" and "我刚喝了一大杯水，现在又想喝水了"。

2. “他的脸白得象雪一样”。Normally, no body will say "这个考试难得没有人考完了。". We can say "这次考试很难，以致于没有人及格。"

3. 我刚到，他就出去了。You can say "我刚到" or "我到了"，but can't say "我刚到了". Sometimes, we say “我刚才就到了”, but it's meaning not same.

4. 她笑得像多花。

6. A 还没 done some light thing, B 就 done some heavy thing.

我还没完成第一部分的题目，他已经全部做完交卷了。

7. 照样 means the environment has changed, but someone still do something just like he did not felling the different.

我星期天已经告诉她我们分手了，但她照样每天给我发短信。

由于家里没钱，他辍学了，但是他照样每天做作业。