They invade a host cell and their genetic material in structs that cell to make copies of the invading ceils, which then infect more host cells.

• 当它们侵入宿主细胞，其遗传物质便指令宿主细胞复制入侵细胞遗传物质的拷贝，然后后者又可感染更多的宿主细胞。