释义：
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。
