carry the can 背黑锅

I will not carry the can for his fault that broke the other's window.
我不会替他打破别人窗户这件事背锅

take…with a grain of salt 对…半信半疑

I suggest you take his words with a grain of salt ,because he really loves playing tricks on others.
我建议你对他说的话半信半疑，因为他老爱耍诡计了

be up in the air 悬而未决

Given my average points aren't enough, my plan for studying aboard is yet up in the air.
考虑到我的平均分还不够，我的留学计划还不能下决定。

whistle in the dark 虚张声势

He seems confident that he can pass the exam, but I believe he's just whistling in the dark.
他看上去对通过考试很有信心，其实是装的

go to seed（人）不修边幅 （物）因无人照料而显得破败

Since the coronavirus epidemic erupted, Jeff started going to seed the whole day .
自从新冠肺炎病毒爆发，Jeff就开始整天不修边幅的。

on the wrong foot 出师不利

Their relationship started off on the wrong foot, but they got along better afterward.
他们一开始关系不好，但后来好多了

a black look 恶狠狠地瞪一眼

I knew what I did was wrong, and I tried to apologize to her, but sha gave me such a black look that I realized it wasn't a good time.
我知道我的行为是错的，我也尝试跟她道歉，但她给我这么一个眼神我就知道现在还不是恰当的时间。