So,Once they are lost in response to a toxic sound or to an antibiotic it cannot be regenerated by natural means.

一旦因噪音或抗生素遭受损失,就难以再生。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

And after a toxic insult, they are gone. This is what the inner ear of a person who is deaf looks like.

受到损伤后，毛细胞没了，耳朵失聪的人的内耳就是这幅摸样。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

And in terms of thinking about it for organic chemistry or if you're interested in thinking about the mechanism maybe by which it is toxic, a first step would be to draw its Lewis structure.

而为了在有机化学中思考它,或者如果你对它,有毒的机理感兴趣的话，第一步要做的应该就是画出它的路易斯结构。

麻省理工公开课 - 化学原理课程节选

However, their biological relatives in Mexico would presumably have that same risk, but it would never be manifested if they're not exposed to what some have called a toxic food and physical activity environment.

而且,他们远在墨西哥的血缘亲属,可能也面临同样风险,但他们面临着所谓的有毒食物和活动环境,这个说法就不会得到证实

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Cyanide is incredibly toxic, it's a poison.

氰化物有极高的毒性，它是一种毒药。

麻省理工公开课 - 化学原理课程节选