词汇点睛
prevent v.阻止;预防
[观察] Can people prevent certain accidents?人们能阻止某些事故吗?
Nobody can prevent him from going there.没有人能阻止他去那儿。

探究 prevent是及物动词，意为“阻_”,后面可接名词、代词作宾语。prevent...(from) doing sth.意为“阻止.....做某事”，相当于stop.….(from) doing sth.和keep...from doingsth.。
We must take steps to prevent the earth from being warm.我们必须采取措施阻止地球变暖。