题目

在盛有水的电解槽中加入含等物质的量的Ag+，Pb2+，K+，SO42-，NO3-，Br的物质-，充分搅拌，然后用惰性电极电解，通电片刻后，氧化产物和还原产物的物质的量之比为 A.1：2        B. 8：1          C.  1：1        D.80：108 答案：A 解析: 略Do you want to have a mobile phone? Have you had a mobile phone already? Nowadays more and more students have their own mobile phones, and mobile phone use has become a problem for middle schools. Some middle schools in China have banned students from carrying mobile phones during school hours.Mobile phone use among children has become a big problem for the school this year. Some children have got mobile phones as birthday gifts, and more students want them.Wang Pi, an official, said, “Mobile phone use is a distraction (分散注意力的东西) to students during school hours and it also gives teachers so much trouble in their classrooms.” Teachers were also saying that sometimes students might use phone messages to cheat during exams.Wang Pialso said some schools had tried to ban mobile phones, but some parents felt unhappy because they couldn’t get in touch with their children.Many teachers said students should not have mobile phones at school, but if their was a good reason, they could leave their phones at school offices. They also said there were many reasons why the students should not have mobile phones at school. They were easy to lose and were a distraction from studies.Many people say that they understand why parents would want their children to have phones, but they think schools should let the students know when they can use their mobile phones.小题1:Some middle schools have banned students from carrying mobile phones         .A．because they are studentsB．because they don’t earn moneyC．when they are at schoolD．when they are free小题2:Some parents felt unhappy because they couldn’t        during school hours.A．help the teachers with their workB．leave their mobile phones at school officesC．use their mobile phonesD．get in touch with their children小题3:The three underlined words “they” in Para. 5 refer to       .A．teachers; students; mobile phonesB．teachers; mobile phones; studentsC．students; teachers; mobile phonesD．students; mobile phones; teachers小题4:The passage tells us that         .A．it is impossible to ban students from using mobile phones at schoolB．some parents felt unhappy because they couldn’t use their phones at schoolC．students shouldn’t have mobile phones at school except for some special reasonsD．parents should teach their children how to use mobile phones during school hours