题目

     If you' re planning on going on a vacation, you need to make sure that you travel light as the price of your overweight baggage is sky rocketing．Below are a few tips that would help you pack light．      Choose your suitcase wisely      First and foremost you need to buy a suitcase in order to pack your stuff．But, when buying one you need to make sure that it' s light and strong．There are plenty of different brands to choose from, you need to choose wisely as some of them even though they may be extremely light would be really very expensive．      Create 一个氘核和一个氚核聚合成一个氦核的反应方程是12H+13H→01He+01n，此反应过程产生的质量亏损为△m．已知阿伏伽德罗常数为NA，真空中的光速为c．若1mol氘和1mol氚完全发生核反应生成氦，则在这个核反应中释放的能量为（　　）A．12NA△mc2B．NA△mc2C．2NA△mc2D．5NA△mc2