are：过去式： were；过去分词： been

are意思：

v./aux.是（be的第二人称单复数现在时，第一、三人称复数现在时）

n.公亩(等于100平方米)

例句：

The first part of the plan has been safely accomplished.

计划的第一部分已顺利完成。

There are four GPs in our local practice.

在我们地区诊所有四个全科医生。

I've been trying to contact you all day.

我整天一直在设法与你联系。

There has been some decrease in military spending this year.

今年的军费开支有所减少。

We were friends and colleagues for more than 20 years.

20多年来我们既是朋友又是同事。