inhibit和restrain,constrain有何区别?

inhibit抑制
eg.A substance used to kill or inhibit the growth of algae.
杀藻剂用来杀死或制止水藻生长的物质
Constrain表示力劝,强迫,常用于constrain sb.to do sth.；
eg.She tried to constrain herself from a cough in class.
上课时她竭力忍住不咳嗽.
Refrain克制,多用于refrain from doing sth.指克制自己以避免做某事；
Restrain制止,多用于restrain sb.from doing sth.指控制他人不去做某事；
eg.Please refrain from feeding the monkeys.
请勿给猴子喂物.