buy的過去分詞是什么

　　例句：

　　You would do well to consider all the options before buying.

　　你購買之前最好對各種選擇都考慮一下。

　　We buy our fruit and vegetables at the market.

　　我們在市場上購買水果和蔬菜。

　　Now is a good time to buy a house.

　　現在買房子正是時候。