on.off代表开和关

例句

1、

September was a long way off.

那时离九月份还有很长一段时间。

2、

The ship lay at anchor two miles off the rocky coast.

船在离岩岸两英里处抛锚停泊。

3、

Some people don't know when they're well off.

有些人身在福中不知福。