think/think of/think about在意思和用法上有什么区别，可以造句说明吗，谢谢

think
vt.
1. 想;思索[+wh-]
Think how much you can earn if you open a restaurant in such a good location.
想一想,要是你在这样的黄金地段开一家餐馆,你会赚多少钱啊。
2. 认为,以为[O8][O9][+(that)][O2]
We thought it our duty to take care of the orphans.
我们认为照顾这些孤儿是我们的职责。
They thought the novel worth reading.
他们认为这本小说值得一读。
I think he will come.
我想他会来的。
3. (常与cannot, could not连用)想像;理解[+wh-]
I can't think what you mean.
我不懂你是什么意思。
I can't think why they left without saying good-bye.
我不明白他们为什么不告而别。
4. 记忆,想起[+wh-]
I can't think what his phone number is.
我记不起他的电话号码是多少。
5. 想要,打算[+to-v][+(that)]
At first he thought to tell her, then he changed his mind.
他原来打算告诉她的,后来改变主意了。
6. 预料,料想[+(that)][+to-v]
I didn't think to land myself in trouble.
我没想到会使自己陷入困境。
vi.
1. 想;思索[(+about)]
Think before you leap.
先思而后行。
2. 认为
Do as you think best.
你认为怎样最好就怎样去做。

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