题目

在研究自感现象的实验中，用两个完全相同的灯泡a、b分别与自感系数很大的自感线圈L和定值电阻R组成如图所示的电路（自感线圈的直流电阻与定值电阻R的阻值相等），闭合开关S达到稳定后两灯均可以正常发光. 关于这个实验下面的说法中正确的是        A．闭合开关的瞬间，通过a灯和b灯的电流相等        B．闭合开关后，a灯先亮，b灯后亮        C．闭合开关，待电路稳定后断开开关，a、b两灯过一会同时熄灭        D．闭合开关，待电 阅读理解 　　Have you heard of the term “tweenager”? It’s a new word being used in the UK to describe children at about 10-12 years old．Why are the media suddenly referring to kids in this way? Well, more and more companies are beginning to create products and services for tweenagers．The Disney company sells the Hannah Montana television show, music, films and products to tweenagers and their parents．You can get everything from branded lunchboxes and cellphones, to fan magazines and clothing．The High School Musical series of films is also intended for a tweenage audience．So, it’s all about sales, which tells us tweenagers must have more money, freedom and influence upon their parents than they have ever had before． 　　Most children in the UK today get more pocket money than kids did a decade ago．In spite of the credit trouble, parents have more money to give than previously, since parents are having fewer children on average than in the past．addition, divorce rate in the UK is continually rising and In the parents spend less time with their children than they used to．So, many parents are under constant pressure from commercial marketers and the requests of their children． 　　You may wonder how tweenagers have more freedom than previous generations．Well, UK children today are very good at using media and computers．A lot of them have a television, if not a computer, in their bedrooms．They have access to much more information about life and the world．They may have experienced a lot in life as well, since 25％ of UK children live in single －parent families．People now say that“kids are getting older younger”．With such sophistication(世故)at such a young age, it’s no wonder that tweenagers are able to influence their parents． 　　UK tweenagers never used to be worried about spending money on fashionable clothes．That’s changed．Now, they are concerned about the fashions and their images．In a world of television programs that promise overnight success and fame at a young age, some people think it’ s very important to look fashionable．Such ideas are also promoted by both Hannah Montana story, in which a tweenage girl suddenly becomes a world－famous pop star, and the High School Musical story, in which tweenagers go through various auditions(试演)for musicals and talent shows． (1) The underlined word “they” in the second paragraph most probably refers to “________”． [　　] A． companies B． sales C． tweenagers D． their parents (2) Why are UK children given more pocket money than before? [　　] A． Their parents earn more money． B． There are fewer children in a British family． C． They spend more money on books． D． Most of them live in single－parent families． (3) Compared with previous generations，UK tweenagers today ________． [　　] A． have less effect on their parents B． are more worried about their careers C． have fewer life experiences D． know more about the world (4) We can make a conclusion that ________． [　　] A． the television programs have a great influence on UK tweenagers B． UK tweenagers benefit a lot from the television programs C． the Hannah Montana television show appeals to a lot of old viewers D． it is wise to encourage kids to be like adults at such a young age