这些形容词均表示“致命的”之意。
deadly : 指能致命或实际已致命的事物，也可指企图致死他人的人。
- a deadly virus
致命的病毒 - a deadly weapon
致命的武器
fatal : 正式用词，强调死亡的不可避免性，多用于指伤或疾病等。
- This illness is fatal in almost all cases.
这种病几乎是不治之症。 - the fatal shooting of an unarmed 15-year-old
对手无寸铁的15岁少年的致命枪击
mortal : 语气强，指导致死亡的直接原因，也指人终有一死的。
- a mortal blow/wound
致命的一击 / 伤口 - to be in mortal danger
处于极度的危险之中 - Her reputation suffered a mortal blow as a result of the scandal.
这一丑闻毁了她的名声。 - For all men are mortal.
人终有一死。
lethal : 指由于某物本身具有致命的性能。
- Three minutes after the fire started, the house was full of lethal fumes.
起火3分钟后，房子里充满了致命的毒气。 - In the car the police found guns, knives, and other lethal weapons (= weapons that can kill).
警察在车里找到了枪支、刀具及其他一些凶器。 - A 59-year-old man was executed by lethal injection (= by having a poisonous substance put into his body) this morning.
今晨一位59岁的男性罪犯被执行注射死刑。 - That combination of tiredness and alcohol is lethal (= has a very bad effect).
身体的疲劳加上酒精的作用会产生非常严重的后果。
