题目

区分下表中的各组物质，所选择的方法或试剂不正确的是选项物质鉴别的方法或试剂A葡萄糖和面粉灼烧后看残渣颜色B碳酸氢铵与蔗糖加热后闻气味C10%的氯化钙溶液与10%的硫酸钠溶液肥皂水D铁片与锌片磁铁 A. A B. B C. C D. D 答案：【答案】A【解析】A、葡萄糖和淀粉燃烧均由褐色固体残渣出现，现象相同，无法区分，选项错误；B、碳酸氢铵与蔗糖分别加热后，产生刺激性气味的是碳酸氢铵，无味的是蔗糖，选项正确；C、加入肥皂水后，产生浮渣的是10%的氯化钙溶液，产生泡沫的是10%的硫酸钠溶液，可以区分，选项正确；D、能Calling the futureWhen American inventor Alexander Graham Bell invented the telephone in 1876，it was a revolution in communication. For the first time, people could talk to each other over great distances. Over the last two decades a new means of spoken communication has appeared ：the mobile phone.The mobile phone is like a two-way radio. But the two-way radio is a limited means of communication. As soon as the users move out of range of each other's broadcast area, the signal is lost. In the 1940s, researchers experimented with the idea of using a number of radio masts（无线电杆）to pick up signals from two-way radios. A caller would always be within range of one of the masts. When he or she moved too far away from one mast, the next mast would pick up the signal. （Scientists referred to each mast's reception area as being a "cell". This is why in many countries mo-bile phones are called "cellphones".）However，1940s, technology was just at the beginning. The "mobile phones" were huge boxes. They had to be moved by car.The first real mobile telephone call was made in 1973 by Dr Martin Cooper. As soon as his invention was complete, he tested it by calling a rival （竞争对手）scientist to announce his success. Within a decade, mobile phones became available to the public.They have changed the way we do a lot of things. One powerful feature is: the short message service（SMS） or text message. It's the perfect communication method for the busy modern lifestyle. The text message has changed the way we write in English. The language construction became more lax （松散的）. Traditional rules of grammar and spelling are much less important.Over the last few years mobiles have become more and more advanced. We have seen the introduction of cameras, global positioning system and Internet access.Alexander Graham Bell would be surprised if he could see how far the science of the telephone has developed in less than 150years. If he were around today, he might say ： " That's gr8! But I'm v busy rite now. Will call U 2nite. "【1】 The article is written to __________.A. warn people of the possible risks in using mobile phonesB. inform readers of the history and development of mobile phonesC. convince people of the uses of mobile phonesD. predict the applications of mobile phones【2】 What's the CORRECT time order about the development of communication?a. the telephone invented by Alexander Graham Bellb. "mobile phones" with very large boxesc. mobile telephone call made by Dr Martin Cooperd. mobiles with cameras, GPS and Internet accessA. a, c，b, d B. b, a，c, d C. a, c，d, b D. a, b，c, d【3】 The last sentence of the whole passage "That's gr8 ！ But I'm v busy rite now. Will call U 2nite. " may probably mean __________.A. That's great! But I'm very busy right now. （I）Will call you to-nightB. It's eight now. I'm very busy. （I） Will call you tonightC. That's great! But I'm busy writing now. （I） Will call you at two tonightD. "8" is great! But I'm very busy right now. （I） Will call it "U" to night【4】 What do you think of the author according to the last paragraph?A. Humorous B. Ironic C. Kind D. Worried