题目

阅读短文，根据短文内容回答下列问题或翻译句子。It was very cold .It snowed heavily and blew very strongly . It was not a good night to go out . But David had to walk home from work .I can be warmer , he thought ,I wear my coat backwards (反方向地).He took off his coat and put it on backwards That's much better. He thought and walked on . About ten minutes later a car hit him. The driver stopped his car and got out of it .He ran to help David .Soon a police car arrived .The policeman ran to look at David .I'm afraid he's dead. The policeman told the driver .The driver下列关于氯的说法正确的是A.Cl2具有很强的氧化性，可以使有色布条褪色B.Cl，为不同的核素，有不同的化学性质C.实验室制备HCl可用排饱和食盐水集气法收集D.25℃时，1克氢气所含质子数为NA个（NA表示阿伏加德罗常数）