as safe as houses

见house

in safe hands

safe in the knowledge that

used to indicate that one can do something without risk or worry on account of a specified fact

（用于表示因掌握了某种所说明的情况，做某事无风险或无需担忧）因了解…情况而做某事有把握

they used to recruit hundreds a year, safe in the knowledge that many would leave.

他们过去一年招收数百人，因为他们知道很多人会离去。

to be on the safe side

in order to have a margin of security against risks

为稳妥起见；以防万一

to be on the safe side, she had recorded everything.

为稳妥起见，她把一切都记录下来。