松劲的英文：
letdown

You shouldn't slacken off in your study.
你在学习上不应松劲。

Redouble your efforts and not slacken off.
要再接再厉，不能松劲。

We mustn't let up,even though we're winning.
我们即使快赢了也决不可松劲。

Come on, keep at it, you've nearly finished!
加油，别松劲，你眼看就完成了！

Don' t slack up your effort, as we are getting to the end
快到完成的时候了，别松劲啊。

We're on the last lap, so don't slacken!
我们已处最後阶段, 可不要松劲啊!

I never slackened the strokes of my piece of chino upon the brass.
我手上那块布还不住地擦着铜牌，一刻没有松劲。

I never slackened the strokes of my piece of chino upon the brass
我手上那块布还不住地擦着铜牌，一刻没有松劲。

Not getting an invitation to the party is a big letdown for Jill.
没有接到参加晚会的邀请，吉尔感到十分失望。

It was a big letdown when I was not accepted by Harvard university.
当我的入学申请被哈佛大学拒绝时，我失望极了。

It was a big letdown when I wasn't accepted by Harvard University.
〞当我的入学申请被哈佛大学拒绝时,我失望极了。〞