关于下列甲、乙电路图说法正确的是 A．甲图中滑动变阻器R0属分压接法 B．甲图 发布时间：2017-05-20 17:51 │ 来源：www.tikuol.com 题型：选择题 问题： 关于下列甲、乙电路图说法正确的是A．甲图中滑动变阻器R0属分压接法B．甲图中电阻R两端的电压能从零开始调节C．乙图中滑动变阻器R0属限流接法D．乙图中电阻R两端的电压能从零开始调节
题型：选择题 阅读理解。 Some children wish to be writers some day. They want to write stories or books for people to read. That's good! It's good to write something for people to read! But they should know that they need to be good readers first before they are really good writers. They should read a lot of books, instead (代替) of watching TV and spending a lot of time playing games when they are free. There is more fun in reading, so you want to look for more books to read. Before you decide to be a good writer, you'd better say to yourself,"I must read more and more!" 1. This article mainly tells us that _____. [ ]A. some children wish to be writers some day B. it is good to write something for people to read C. reading can be helpful for us to become a good writer 2. Some children want to be writers _____. [ ]A. because they want to be good readers B. to write stories or books for people to read C. to find good work some day 3. It's good for children _____. [ ]A. to do a lot of reading B. to watch TV in the evening C. to have wishes only 4. Reading can _____. [ ]A. help you to be a good player B. help you write well C. make you work better 5. From the passage we know that _____. [ ]A. all children like to be writersB. people like to read for children C. children need to read more and more books 查看答案
题型：选择题 （8分）1.t℃时，某稀硫酸溶液中c（H+）=10－a mol·L-1，c（OH－）=10－b mol·L-1，已知a+b="13" ：（1）该温度下水的离子积常数K w的数值为 。（2）该温度下（t℃），将100mL 0.1 mol·L-1的稀H2SO4溶液与100mL 0.4 mol·L-1的NaOH溶液混合后（溶液体积变化忽略不计），溶液的pH= 。（写出计算过程）（3）常温下pH=5的H2SO4的溶液稀释500倍后，溶液中SO42-的浓度与H+浓度的比值约为 （写出计算过程） 查看答案
