Viruses can exist either extracellularly or intracellularly.

病毒可以存于细，可以存于细。

They can exist either extracellularly where the virus is inactive and isn't capable of reproducing or intracellularly where the capsid is removed and the virus becomes active.

它们可以存于细，处于不活跃状态，无法复制，或者细，脱掉衣壳，变得活跃。