走进,进入;介入,干涉
step in v 1: get involved, so as to alter or hinder an action, or through force or threat of force; "Why did the U.S. not intervene earlier in WW II?" [syn: {intervene}, {interfere}, {interpose}] 2: act as a substitute; "She stood in for the soprano who suffered from a cold" [syn: {substitute}, {deputize}, {deputise}]