题目

阅读理解 Do you have any stress in your daily life and do youknow how to reduce your stress? Our world is changing with ever increasing speed andmany people are finding it difficult to keep up with it. Although no one cancontrol the world at large, people do have the power to control their personalworld by controlling stress and their responses (反应) to it. Of course a certain amount of stress, both physicaland mental is normal and healthy for humans but too much can be fatal. According to a report on the MayoClinic's website, 80% of patient visits to their doctors are stressrelated. A元素“氦、铷、铯”等是用下列哪种科学方法发现的： A．红外光谱         B．质谱           C．原子光谱          D．核磁共振谱