条件致死突变（conditional lethal mutation)

The chemical is lethal to rats but safe to cattle. A: toxic B: harmful C: deadly D: contagious

That airplane crash dealt a _____ blow to this airline company. A: light B: lethal C: important D: subtle

ED50 means A: Median effective concentration B: Median toxic dose C: Median lethal dose D: Median effective dose

Cambridge English Corpus defines 'euthanasia' as: "There may be many intentions present in a single action, and in complex actions such as euthanasia and lethal palliation there typically are."

What can be inferred about the effective volcanic ash on people (). A: It’s lethal upon contact. B: It has relatively little harmful effect. C: It affects the sense of hearing.

The life cycle of virulent phages that always kill their host cell and never become inactive prophages would be the _____ cycle. A: lethal B: lytic C: temperate D: strict E: lysogenic

Many smokers believe that e-cigarettes can help them quit smoking. _____________, scientific researches show that e-cigarettes are more addictive and lethal than traditional cigarettes. A: In addition B: However C: As a consequence D: Equally important

电子系统中的高电压可能致命。 A: High voltage in the electronic system can kill you. B: High voltage in the electronic system can be deadly. C: High voltage in the electronic system can be fatal. D: High voltage in the electronic system can be lethal.

Beekeepers use smoke to calm<br/>bees when they are collecting honey or relocating a hive. Bees make<br/>honey to feed their young and so they have something to eat during<br/>the winter. People attacked by killer bees suffer numerous stings<br/>and may experience fatal allergic reaction. / What statement can we<br/>make from the information given in the short passage?<br/>____ A: Bees<br/>can produce smoke when they are collecting honey or relocating a<br/>hive. B: Bees<br/>make honey for human beings. C: Beekeepers<br/>use honey to feed their young. D: Killer<br/>bees are so dangerous that they might be lethal.