题目

用恰当的化学用语回答下列问题：    ⑴两个氢分子________  ；（2）n个硫酸根离子_______；（3）五氧化二氮中氮元素    显 +5  价___________；（4）最简单的有机物是___________；纯碱_______。 答案：2H2    nSO42-   P2O5    CH4   Na2CO312．假如你是李华，暑假将有来自英国的三十位同学来你校交流学习，你给英方负责人Mr．Cave写封电子邮件，申请派一位同学住到你家里．开头结尾已经给出，不计入总词数．邮件内容要求包括以下三个方面：（1）简要描述一下你的家；（2）你希望你想接待的同学是一个什么性格的人；（3）你打算向这位同学介绍中国的什么．注意：（1）70词左右；（2）文中不能出现可能透漏考生真实身份的任何信息．Dear Mr．Cave，I am very happy to have a student in my home．There are three people in my family，and my parents are very friendly．Also，it is just takes 15 minutes'walk from my home to school．I am an outgoing boy who loves sports，especially basketball and football，so I hope he is the same as me．Therefore，we can share a lot of interesting things and play sports together．My spoken English is quite good，if he comes to my home，I will teach him Chinese，tell him some Chinese culture and introduce him to my friends．I am sure he will enjoy himself at my home．I am looking forward to your reply．Yours sincerely．Li Hua．