题目

设阿伏加德罗常数的值为NA，下列说法中正确的是A．1mol苯乙烯中含有的C＝C数为4NAB．2.8 g乙烯和丙烯的混合气体中所含碳原子数为0.2NAC．0.1molC nH2n+2中含有的C－C键数为0.1nNA    D．标准状况下，11.2 L己烷所含分子数为0.5 NA  答案：B解析: —How soon will the candidates get their university admissions?—It may take three weeks for all the applications to be ________.A．withdrawn B．delivered C．edited D．processed