quiet down 安静
When he quieted down, I began to tell him the truth.
当他平静下来时，我开始告诉他实情
Please keep quiet while others are studying.
在别人学习的时候,请保持安静。

hold out坚持要求,坚持到底
How long can we hold out against these attacks?
我们对这些攻击能抵抗多久?
I guess I can hold out a little longer.
我或许还可以再忍一阵子