如果你想攻占一个大型的旧式堡垒，你必须要有很多大炮来对付那些缩在城堡中的敌人。

If you want to capture a large old fort, you must have a lot of cannons to deal with the enemies who shrink in the castle.

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如果你想要发展好的关系，在需要的时候必须要有自信，拿出主见来。

If you want good relationships, you must have the confidence to be self-assertive when required.

《柯林斯英汉双解大词典》

与用作被人识别的信号相比，如果用作照亮路途的头灯的话，光源必须要明亮很多。

The light source must therefore be immensely brighter if it is to be used as a headlight to illuminate the path, than if it is to be used as a signal to others.

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From moment to moment, language changes, but if we're to understand it as language we have to honor its simultaneity.

语言无时无刻不在变化，但是如果我们要理解它,我们就必须尊重它的同时性。

耶鲁公开课 - 文学理论导论课程节选

If they're going to survive thinking about this case at all, we need to throw in a no branching rule.

如果要让这个案例说得通，我们必须加入无分支规则。

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If you have a set of blocks, mechanical, physical blocks,and I tell you to build something and I say, oh, by the way, you have to cut the blocks in smaller pieces, you are going to get angry, aren't you?

如果你要一个区块，力学的，物理区块，我告诉你要去建造东西,我说，顺便说一下，你必须将一整区块切成小块，你会生气，不会吗？

麻省理工公开课 - 固态化学导论课程节选