Lock the stable door when the horse is stolen.

例句：

1. 1. Please lock the door when you leave.
   当你离开时，请把门锁上。
2. 2. The thief quickly locked the safe before he could escape.
   那个小偷迅速锁上了保险箱，以便逃脱。
3. 3. She locked the door and turned off the lights before going to bed.
   她锁上门并关灯后才去睡觉。