A：I'm terribly nervous.
我很紧张。
B：Calm down!
冷静下来!
注释：
a.nervous为形容词，表示“紧张的”，由名词nerve转变而成。
nerve可作“神经”解，是可数名词;也可表示“勇气”，此时则为不可数名词。
例：He doesn't have the nerve to pursue that girl.
= He doesn't have the guts to pursue that girl.
(他没有勇气追那女孩。)
* pursue vt.追求
b.想缓和对方情绪时，可说：
Calm down.
= Cool down./Cool off.
(冷静下来。)