It's reproduction of the virus and passage of that virus onto new cells which causes the problems with disease that we associate.

病毒一旦繁殖并进入新细胞,就会带来相关病症的危害

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You have to exclude those causes that generate moral hazard problems for the insurance to work; otherwise, the whole system will fail.

你得将一些,有可能会产生道德风险的情况,排除在外;,否则，整个保险系统就失效了。

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