题目

下列关于声现象的说法正确的是A. 声音在各种介质中的传播速度一样大B. 只要物体在振动，我们就一定能听到声音C. 减弱噪声的唯一方法是不让物体发出噪声D. 拉二胡时不断地用手指控制琴弦，是为了改变音调 答案：【答案】D【解析】A、声音在不同介质中的传播速度不同，一般情况下声音在液体中传播的速度小于在固体中传播的速度，大于在气体中传播的速度；B、声音的传播是需要介质的；C、减弱噪声有三种：①在声源处减弱；②在传播过程中减弱；③在人耳处减弱；D、琴弦的长度不同，振动的频率不同，发第三部分阅读理解（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）　　阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。A　　Chinese cigarette packs will have skulls(骷髅),blackened teeth or diseased lungs printed on them in the latest effort to deal with smoking,but one expert said the images may actually attract younger people to take up the habit.　　The images would have to take up at least 30 percent of the pack's surface area under rrules that would come into force from January 2009.It was part of a plan that would also see tobacco advertising banned in China by 2011.Similar images are already printed on packs in countries including Singapore,Thailand and Canada.　　Chinese are the world's most enthusiastic smokers,with a growing market of more than 300 million making it a magnet for cigarette companies and a focus of international health concern.China has banned smoking on public transport,but it is still allwed in many public places such as restaurants,and it is not uncommon to see people smoking in hospitals.　　The average age people take up smoking in some parts of the country had hallen to as low as just over 10.And the new measures could make the problem worse,according to Zhao Cuiping,a youth expert."In analysis over the past decade(十年) on what young people like,they far prefer skulls and other scary images to cats or dogs,"she said.　　Chinese cigarettes are also among the cheapest in the world and a packet can cost as little as eight US. cents.　　The country needs to take effective measures to cut down smoking or the habit could end up killing 2.2 million Chinese a year by 2020,the World Health Organization said in May.　　56.The new designs will be adopted on cigarette packs ______. 　　　A.to attract young people     B.increase tobacco sales 　　　C.as trade mardks           D.as health warnings 　　57.We can infer from the article that nobody is allowed to smoke while _____ in China now. 　　　A.staying in a hospital B.taking a bus ride C.eating outsede D.walking in the street 　　58.Zhao Cuiping seemed to think that teenagers would ______. 　　　A.enjoy the new cigarette packs 　　　B.dislike the new measures 　　　C.be the last to give up their smoking habit 　　　D.prefer to have pet animals on the packs 　　59.All the paragraphs support the idea that China's smoking problem is serious except ____. 　　　A.Paragraph 1 B.Paragraphs 1 and 2 C.Paragraphs 1and 5 D.Paragraphs 2,5 and 6