They did their best to keep on their guard.

他们尽量保持警惕。

youdao

Keep on keeping on and do not let down your guard.

继续努力奋斗，千万不要放松警惕。

youdao

Keep on keeping on and do not let down your guard.

继续努力奋斗，千万不要放松警惕。

youdao