When anacron runs, it checks to see if the required number of days has passed since the job was last run and runs it if necessary.

当anacron运行时，它检查自作业上一次运行以来是否已经经过了所需的天数，如果需要，就运行作业。

youdao

It may be necessary to clear the cache manually if the data source data changes infrequently or if it is required to clear the cache in between automatically scheduled cache clearing.

如果数据源数据很少变化或需要清理自动调度的缓存清理之间的缓存，那么手动清理缓存可能就是必须的。

youdao

If necessary, the MarCom Coordinator will call the attendants to check if pickup service is required.

如果需要的话，公关部助理应与受邀者确认是否需要接车服务。

youdao

Indeed, they would gladly mortgage their own lives, give away every cent they will ever earn and, if necessary, turn to bank robbery if that is what is required to save the life of their child.

FORBES: Anecdotes vs. Economics in Health Care Policy

He will be in constant communication and get regular briefings from his national security team, as well as his economic team, and he will, of course, be fully capable, if necessary, of traveling back if that were required.

WHITEHOUSE: Press Briefing

The mandate is seen as necessary if insurance companies will be required to guarantee issue of health insurance policies and cover pre-existing conditions.

FORBES: Middle District of Pennsylvania Rules Three Obamacare Provisions Unconstitutional