1·The cavalry charged down on the defenceless villagers.
骑兵向手无寸铁的村民们冲了过去。
1·The bandits descended upon the defenceless village.
匪徒袭击无防御的村庄。
2·Scientists have found that viruses may sometimes remain inactive FOR years, but can quickly infect any defenceless cell.
科学家发现病毒有时可处于不活跃状态达数年时间,但是能突然感染任何无防御的细胞。