购买使用公车的英文：
buy and use government cars

buy是什么意思：
n. 所购的物品；便宜货；买卖
v. 买；获得；购得；收买；相信

Buying bonds is safer than buying stocks.
买债券比买股票风险小。

It's a good buy at that price.
这是一笔价钱合算的买卖。

That shirt was a really great buy.
这个衬衫真是便宜货。

use是什么意思：
v. 用，运用；对待；耗费；服食；利用
n. 使用；用途

It is used as a reflexive.
它被作为反身代词使用。

That was a balk to us.
那对我们是个挫折。

They help us to be maximal encouraging to us.
他们来帮助我们对我们是个极大的鼓舞。