Well, what it is is easily enough explained despite the sort of difficulty and thorniness of the word.

虽然我们遇到过很多困难和挫折,但这个问题很容易解答。

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Now, as I said last time, the subject of free will--or free will, determinism, causation and responsibility, this cluster of problems-- is an extremely difficult and complicated physical problem.

正如我上次所说的,自由意志这个主题 或者说自由意志,决定论,因果论,责任,这一堆问题,是极端困难和复杂的物理问题

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