题目

用电子式表示下列物质的结构： （1） NH4Cl； （2） Na2O2； （3） CO2； （4） MgCl2；（1）～（6）中，仅含离子键的是，仅含共价键的是，既有离子键又有共价键的是． 答案：【1】 【1】 【1】 【1】【2】（1）（2）（4）【3】（3）【4】（1）（2）你收到一封咨询信，请你以旅行社工作人员的身份完成任务。 Dear Ace Travel, I'm Li Ming, from the east of China. For the coming winter vacation, my family and I want to spend our vacation in a foreign city for ten days. We would like to go somewhere not only warm but also interesting. We don't mind how far we have to go. It has to be a place where we can swim everyday, and it would be nice if our hotel is not expensive but clean and comfortable. We like to pay no more than $ 5,000 for the trip. Could you please give us your suggestions for vacation spots? Thanks a lot. Yours, Li Ming 请你根据来信，从下列所给的地方中选择一个或两个符合Li Ming要求的地方，向他提出建议。（80字左右）Tokyo, Sydney, Hawaii, Shanghai