a quantity of

例句：

1. 1. We need to buy a quantity of vegetables for the dinner.
   我们需要买一些蔬菜做晚餐。
2. 2. The store sells a variety of products in this quantity.
   这家商店以这个数量出售各种产品。
3. 3.The teacher asked us to bring a quantity of books to class.
   老师要求我们带一定数量的书到班上。