题目

在①浓硫酸、②氢氧化钠、③稀盐酸、④氢氧化钙这四种物质中选择适当物质的序号填空： （1）常用于干燥二氧化碳气体的干燥剂是 ． （2）实验室用于制取二氧化碳气体的酸是 ． （3）实验室用于检验二氧化碳气体的碱是 ． （4）俗名为烧碱的物质是 ． 答案：【考点】气体的干燥（除水）；二氧化碳的实验室制法；二氧化碳的检验和验满；常见碱的特性和用途． 【专题】物质的性质与用途． 【分析】根据物质的性质进行分析，浓硫酸能吸水可作干燥剂；氢氧化钙显碱性其溶液常用于二氧化碳的检验；氢氧化钠是重要的化工原料，俗称烧碱、火碱、苛性钠完形填空Some years ago, Chinese high school students would show their new schoolbags , new clothes or new pens to their classmates when the new term started . Today, however , all have changed . If you still come back to school only these things , you are falling out-of-date(过时的) . Students in big cities like to bring the latest(最新的) high-tech things to school, and feel happy and to show off（炫耀） these things to . Mobile phones, MP3 players , CD players , electronic(电子的) dictionaries , the list is endless .Young people think that , living in the 21st century , they must keep up with the times . They don't want to fall . Besides, they think that they need to keep in touch with their classmates , so they need mobile phones . They also like to the pop music , so they need CD players . They explain that, like electronic dictionaries , these can be in their study , . They think that their parents should understand they want these things .Foreign students will also bring some latest high-tech things when they to school at the beginning of a new term. However, they often use the money which they made by themselves during the holiday to buy these high-tech things that they want .1.A．to B．from C．of D．with2.A．right B．lucky C．nice D．pleased3.A．other B．the others C．others D．the other4.A．down B．off C．behind D．back5.A．hear B．listen to C．read D．play6.A．look B．just C．feel D．something7.A．new B．modern C．latest D．useful8.A．also B．too C．either D．then9.A．where B．which C．what D．why10.A．return B．return back C．reach D．arrive