I'm not going to have you work long hours on difficult problems to be submitted and then graded.

我的作业不会让你们花费大量的时间,去钻研很难的问题，然后交上来让我打分。

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And if they're a premade salad then it would be even more difficult because you're not constructing it yourself, so it's hard to uses based on these sort of things.

如果那是预制色拉,就更麻烦了,因为那不是你做的,就很难进行统计

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If it were all the things that it's not, or if it were identical to all the things that somehow or another it's not, then I would be in a very difficult situation because I wouldn't have any means of knowing it in particular.

如果一件事就是它自身的反面，或者和其他的事物没有区分之处,那么我们，就很难认识它,因为我们没有办法认识它。

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