back的替换词，keep

keep back:隐瞒留下阻止，同义词:keep  down

例句:

I fought to keep back my tears.

我努力控制住泪水。

The crowds would not keep back from the barrier群众不肯远离栅栏。

keep sb down 压制（或限制、控制）某人

The people have been kept down for years by a brutal regime.多年来人们一直受到残暴统治的压制。

Keep your voice down─I don't want anyone else to hear.小声点——别让人听见