题目

   In conversation, body languages is more important than you might think. Only 71% of our communication is expressed in words. How can we appear calm and confident?    First of all, try to keep still. The old belief that we make up our minds about someone within the first ten seconds of meeting them is untrue. It’s within one-tenth of a second! Therefore, when meeting someone for the first time, try to avoid any small, repetitive(重复的)movements. Take slow, deep breaths and try to keep as still as possible. Your words hold more importance and you can get your ideas heard with现有CO2、O2、CO的混合气体9mL，在密闭容器中点爆炸后，恢复到原来温度和压强时，气体体积变为8mL，再将气体通过NaOH溶液，体积减少5mL．已知同温同压下，气体体积比等于其分子个数比．则原混合气体中CO2、O2、CO的体积比可能是（ ）A．3：1：5B．5：1：3C．1：3：5D．3：4：2