例句：
The curtains were an impulse buy.
这窗帘是一时心血来潮买下的.。
We need to buy some new furniture.
我们需要买一些新家具。
Now is a good time to buy a house.
现在买房子正是时候。
They only buy the best.
他们只买最好的。
Try the shoes on before you buy them.
鞋子要先穿上试一试再买。
It may be necessary to buy a new one.
也许有必要买个新的了。