买买买嗨嗨嗨
冷静 calm down不动声色 maintain one's composurev. shut one's pan其实英语中很多词都可以表达这些意思，具体要看用在哪个句子中比较合适，还有词性的用法要恰当。你可以参考http://www.iciba.com,里面一些句子可以参考。Bill told his story without batting an eyelash, although not a word of it was true.比尔不动声色地讲着他的一套，尽管没有一句是真话。
山水平川
冷静，指人少而静，不热闹或是人沉着而不感情用事。冷静是处理好事情的手段，不冷静处理事情很少会办好事情。那么你想知道冷静用英语怎么说吗?下面我为大家带来冷静的英语说法，供大家学习。
calm
英 [kɑ:m] 美 [kɑm]
sober
英 [ˈsəubə] 美 [ˈsobɚ]
calmness
英 [ˈkɑːmnəs] 美 [ˈkɑːmnəs]
keep calm;
保持冷静
sober-minded
头脑冷静
Keep calm when problems crop up
遇事冷静。
最好保持冷静。
The best thing is to keep cool.
我们在危险的时候应该保持冷静。
We should keep our composure in danger.
我告诫自己要冷下静来。
I told myself to calm down.
他脸上安详的微笑使我们都冷静下来。
His serene smile calmed all of us down.
他温和的回答使她冷静下来。
The softness of his reply calmed her down.
冷静点，既来之则安之吧。
Be calm and take things as they come.
即使在争辩时，你也要尽力保持冷静。
Even when you argue, you should try to keep cool.
一些颜色可以使我们感到冷静，安宁。
Some colors can make us feel calm and tranquility.
这使我变得更冷静，也更凶狠。
This made me colder and more murderous than ever.
没人试着以客观冷静的态度与公司交涉吗?。
Has anyone tried approaching the company with a dispassionate attitude?
她以沉着冷静著称。
She has a reputation for being calm and cool-headed.
如果一方情绪激动，而另一方能保持冷静，那么冷静的一方就掌握了更多优势。”
If one party is emotional and the other stays calm, the unemotional one has far more leverage. “
我要你清醒、冷静。
I need you sane and sober.
学生领袖出现在电视上请求大家保持冷静。
Student leaders appeared on television to ask for calm.
汉口小霸王
楼主的i need to calm down. 最好把to去掉 因为need做一般动词时多用在问句和否定句中。这里need做情态动词。”冷静“的英语表达：calm downkeep coolkeep calmbe oneself
