roll up one’s sleeves 撸起袖子，准备开始干活；准备大干一场

roll 卷

sleeve 袖子

We have a long day ahead, so let's roll up our sleeves and start! 今天将会是漫长的一天，所以让我们撸起袖子，开始干活吧。

I know you're disappointed, but you need to roll up your sleeves and redouble your efforts.我知道你很失望，但你需要卷起袖子加倍努力。