1.ensue的基本意思是继某事之后发生或产生,即接踵而至,常暗示某种逻辑关系的存在,强调按某种顺序行事所产生的必然性。
2.ensue是不及物动词,后常接from表示“由…而产生”“…的结果是”。

ensue from(v.+prep.)
继(某事)而发生,作为(某事)的结果而发生 follow; result from (sth such as action)
〔说明〕 ensue from常不用于进行体。
▲ensue from sth
Who knows what troubles may ensue from overpopulation?谁知道人口过剩会带来什么麻烦?
Bitter argument ensued between us and the bus driver from this misunderstanding.这场误会引起了我们和汽车司机之间的唇枪舌剑。

用作不及物动词
▲S+～(+A)
In his anger he hit the man and a fight ensued.一气之下,他打了那个人,接着是一场搏斗。
A warm debate ensued.接着是一场热烈的辩论。
After the heavy rains, floods ensued.大雨过后,洪水跟随而来。
The train was derailed, and panic ensued.火车出轨了,接踵而来的是恐慌。

ensue, follow, succeed, supervene
参见follow条。