The letter shows that the problem remains unsolved.

他的信显示问题尚未解决。

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And although benign neglect of bubbles no longer appears an option, central bankers are not ready to advocate preemptive popping, because the problem of identifying them early enough remains unsolved.

尽管对泡沫的善意忽略看来已不再是一种选择，央行官员们还没准备好提倡先发制人的去泡沫政策，这是因为在足够早的时候识别泡沫的问题仍然没有解决。

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The problem of induction by simple enumeration remains unsolved to this day.

单纯枚举归纳问题到今天依旧是悬案。

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Even if the European Central Bank goes to zero, the debt problem of governments remains unsolved.

FORBES: Market Holds Breath Ahead Of European Summit