几道初中英语问题

1.Wait till you're more certain.It's better to be sure than sorry.
等到你更确定。有把握比遗憾好。。。
2.What？ He has arrived here already?
什么？他已经到了？
3.Jack can play the violin fairly well but I'm rather poor at it .
杰克能把小提琴拉得还算好但是我相当bad.
4.You dont't believe what I said I am telling the truth.
你不相信我说的，我在说实话
5.The topic of the computer has always interested me.
电脑话题我总是会感兴趣
6.I would have told him the answer had it been possible,but I was so busy then.
我应该告诉他答案是有可能的，可是我是那么忙。。

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我也不知道对不对啦。。你自己再看看吧
可能翻译得有点过分

music is not so useful as science