The maintenance thread looks at each connection in the pool, checks how long it has been in the pool, and how much time has elapsed since it was created and last used.
维护线程在池中查看每个连接，检查连接在池中存放的时间以及连接自创建和最后一次使用以来已经过多长时间。
I first encountered DFA several years ago when I worked on regular expressions, but it has been at least three years since I last used them so I spent some time researching the subject.
几年前，我在处理正则表达式时，第一次遇到了DFA，但是我已经至少有三年没有用过它，所以我花了一些时间来研究它。
But I had at last used the words "your mother" when talking to her before the meeting.
但是，见面前跟她谈话时，我还是用了“你的妈妈”这几个字。
For the duration of the run unit, WORKING-STORAGE items persist in their last-used state.
在运行单元期间，WORKING- STORAGE项将一直保持最后一次使用时的状态。
For the duration of the run unit, WORKING-STORAGE items persist in their last-used state.
在运行单元期间，WORKING- STORAGE项将一直保持最后一次使用时的状态。
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