题目

阅读理解。 “Is there anything else you need, honey？” my dad asked me as he put three twenty­dollar bills in my hand. I was traveling back home from a family visit, and after treating me to breakfast and filling my car with gas, it was obvious that my dad wanted to make sure that I would be okay on the road. “No, Dad. You've done so much already. Thank you！” I was overwhelmed once again by his kind acts of providing everything I needed, despite the fact I just turned 40. Yet I realize that in my father's eyes, I will always be his little girl. He takes deep pleasure in kn下列各物质中分别置于密闭容器中，在一定条件下充分反应，密封容器中的气态物质为纯净物的是（ ）A．分子数为1：1的H2和Cl2B．分子数为1：1的CO和O2C．质量比为1：5的CH4和O2D．质量比为2：3的C和O2