她通常把自己的意见藏在心里。

She usually ___keeps her opinions ___to ___herself.

她把想法藏在心里，她最好的朋友是她的日记。

She ___kept her thoughts ___to ___herself, her best friend being her diary.

你应该对机密信息保密。

You should ___keep confidential information ___to ___yourself.