lean metering

例句：

1. 2.
   指
2. 1. The lean man was able to save a lot of money on his expenses.
   那个瘦男人在开支上节省了很多钱。
3. 2. The car is so lean that it needs oil changes regularly.
   这辆车太瘦了，需要定期换油。
4. 3. The lean-to shelter provided some protection from the rain.
   这个斜顶小屋为人们提供了一些避雨的保护。