step in

verb

1. act as a substitute

e.g. She stood in for the soprano who suffered from a cold

Synonym: substitutedeputizedeputise

2. get involved, so as to alter or hinder an action, or through force or threat of force

e.g. Why did the U.S. not intervene earlier in WW II?

Synonym: interveneinterfereinterpose

1. 介入，干预，插手(棘手问题)
If you step in, you get involved in a difficult situation because you think you can or should help with it.

e.g. If no agreement was reached, the army would step in...
如果无法达成协议，军队将会介入。
e.g. There are circumstances in which the State must step in to protect children.
有些情况下，国家必须出面保护儿童。

1. step in是什么意思

1. 插入,介入：stay by守在一边 | step in插入,介入 | step up提高,加快,加紧

2. 介入;干预;参加：step by step 逐步地,一步步地 | step in 介入;干预;参加 | step up 走近来;登上去

3. 便鞋(有松紧带式)：steer hide閹牛皮 | step-in便鞋(有鬆緊帶式) | step-on便鞋(無鬆緊帶式)

4. 介入：20.profit margin 利润幅度 | 21.step in 介入 | 22.rally 繁荣