So, for example, there's a magician-- The question is not, could I explain to you how the seance manages to do the amazing things that it does?

比如说,有一个魔术师,问题不在于,我能否给你解释通灵任何,做到这些惊人事情的

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You could use "I've already" pattern to explain why you don't want to go to Japan again.

你可以用“I've already”句型来解释你为什么不想再去日本了。

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