题目

阅读理解. Liu Xiang is a famous runner in the world. He was the winner(获胜者) of the Athens Olympics(雅典奥运会) . The Chinese people are proud (自豪) of him. He is a hard-working young man. He is still strong and healthy. Why is he in good health? He usually gets up early in the morning and exercises every day. He likes listening to music and he sings well. He has good eating habits. He never eats junk food and hardly ever smokes and drinks. He goes to bed early and sleeps 8 hours every night. He often says, “It is important(重要) for health to have a good lifestyle.下列符号中，表示两个氮原子的是（ ）A．N2B．2N2C．2ND．