题目

阅读理解 November 11 is Veterans Day in the United States. A veteran is anyone who has served in the armed forces. The term veteran is not just for those who have served in wars. It describes anyone who has ever been in the army. On November11, people hold ceremonies(仪式) and parades(游行) to mark Veterans Day. Public officials take part in the events. Army bands play. And soldiers fire guns into the air to remember those who died in service to their country. The history of Veterans Day relates to World War I. Many people at the time called it the war to end all wars. The United State6．用NA表示阿伏加德常数，下列叙述中正确的是（　　）A．在标准状况下，1L庚烷完全燃烧后，所生成的气态产物的分子数为$\frac{7}{22.4}$NAB．1mol碳正离子CH5+所含的电子数为10NAC．56g铁粉在1mol氯气中充分燃烧，失去的电子数为3NAD．0.5molC3H8分子中含C-H共价键2NA