keep down 减少，降低（声音），抑制，掩藏

　　表示维持在以下 ( down ) ,可以用在一次性降低或减少某物时。进一步可以表示“抑制……”，“阻碍成功”，“掩藏”。

　　例句：

　　Would you keep it down?

　　你能安静点吗？

　　It's not easy to keep you down here like this. But I can't let you out.

　　我知道藏在这里不容易，不过我不能让你出去。

　　If you're so worried about privacy, just wear a hat, and keep your head down.

　　如果你那么担心隐私，大可以带个帽子，低头走过去。

　　对话：

　　A: Keep it down in there. I can't sleep.

　　能不能安静点，我都睡不着了。

　　B: Sorry, we were being so loud.

　　不好意思，我们太吵了。