backdoor

例句：

1. 1.The back door leads to the kitchen.
   后门通向厨房。
2. 2. He slipped through the back door and went into the garden.
   他偷偷地从后门溜进花园。
3. 3. She opened the back door to let fresh air in.
   她打开后门让新鲜空气进来。