For her, books were as necessary to life as bread.

对她来说，书就像面包一样是生活的必需。

Repeat every few days as necessary.

必要时每隔几天重复一次。

Tune your data source as necessary.

必要时需要调优数据源。

Change a "Make changes as necessary."

更改——进行必要的更改。

Adjust your walk schedule, as necessary.

如果需要调整你的步行安排。