题目

设NA代表阿佛加德罗常数的数值.下列说法中正确的是 ①常温常压下, 17g 甲基 (－14CH3) 所含的中子数11NA②常温常压下，22.4L NO气体的分子数小于NA  ③ 64g的铜发生氧化还原反应 , 一定失去2NA个电子 ④常温常压下 , 100mL 0.5mol/L 的乙酸溶液中 , 乙酸的分子数目小于0.05NA⑤标况时 , 22.4L 二氯甲烷所含有的原子数为5NA ⑥常温常压下, 1mol 氯气含有的电子对数为NAA.①②                 B. ③④                C.②④           D.⑤⑥  阅读下面各段，找到相应的问句。 1．How many printers are there in your office? 2．How often do you use your printer? 3．Do you want to have a printer? 4．When do you use your printer? A“I have got a printer in my home．My father buys it for me．I usually use it to print my homework or some information for my lessons from the Internet．I use it in the evening．”Jasmine，Berlin B“I like my printer．I usually print photos or cards．Then I can put them on the wall．I use it three times a week．”Helen，London C“There’re two printers in my office．One is black and white．I often use it to print documents．One is a colour printer．It can print beautiful pictures．”Li Dan，Wefang D“Printers are important（重要的）today．I don’t have a primer now．But I really want to have one．”James，New Youk