vi.
入，进，进入，进去，进来：
Knock before you enter.
进来前先敲门。
入学；参加比赛；报名参加：
Some contestants enter as late as a day before the race.
有些参赛选手直到赛跑前一天才报名参赛。
穿入，刺入：
The sword entered deep.
刀剑深深地刺入。
正式开始；着手处理；开始考虑 (on，upon):
We have entered upon a new phase in history.
我们已