题目

下列离子反应方程式正确的是（   ） A． 氢氧化钠溶液加入过量的碳酸氢钙：HCO3-+Ca2+ +OH-=CaCO3↓+H2O B． 漂白粉溶液吸收少量的SO2：SO2+ H2O+ClO—=SO42—+2H++Cl— C． 向石灰石中加入醋酸：CO32—+ 2CH3COOH=2CH3COO—+H2O+CO2↑ D． 向 FeI2溶液中通入等物质的量Cl2:2Fe2+ +2 I—+2Cl2= 2Fe3++ I2+ 4Cl— 答案：【答案】A 【解析】A. 氢氧化钠溶液加入过量的碳酸氢钙生成碳酸钙、碳酸氢钠和水，离子方程式为：HCO3-+Ca2+ +OH-=CaCO3↓+H2O，A正确；B. SO2被次氯酸根离子氧化为SO42-，且硫酸钙为沉淀，所以漂白粉溶液吸收少量的SO2反应为SO2+ H2O+ClO—+Ca2+=CaSO4↓+2H++Cl—，B错误；C. 碳酸钙难溶于水，不拆成离子形式，正确Hello and welcome to "Words and Their Stories". We will research into some commonly used words and expressions. As with other languages, American English is rich in expressions that come from animals. Today we will talk about the wolf.Wolves are important animals in the traditions and stories of America. Before the Europeans arrived at north America in the 1500s, to native (土著的) Americans, wolves often meant being brave.However, in English, wolves are not to be trusted. Perhaps wolves attacked too many people or ate too many farm animals. Whatever the reason, wolves were killed in many places. So many died that they almost became endangered. They also became known as bad animals.To begin with, there is an expression lone wolf. If we call somebody a lone wolf, he isn't a bad person, but he may like to do things by himself. In fact, he sometimes makes you think he doesn't want to be around people because he dislikes them.Now, let’s move on to the home. Parents tell their children not to wolf down their food. In other words, the child eats too quickly and without care. And if someone says a child was raised by wolves, that child has bad manners and is behaving like a wild animal.A wolf call is the noise made by a man to show that he likes the way a woman looks. But a wolf call is not a nice thing. These men sound rude. And trust me, most women really hate wolf calls. So, they don't help a man in the game of love.By the way, there is a popular expression about wolf from a very old story: a wolf in sheep’s clothing. A wolf in sheep’s clothing describes someone who acts and looks nice on the outside but is bad on the inside. It tells us not to be fooled by appearances.【1】What can we know after reading the passage?A. Wolves are dangerous and should be killed in order to protect other animals.B. Only in American English can we expect to find expressions about wolves.C. In different areas and times, wolves make people think of different things.D. Nobody lived in north America before the Europeans went there in the 1500s.【2】If a person is called a lone wolf, which of the following things is he most likely to do?A. Helping classmates to finish homework.B. Stealing money if nobody is watching.C. Making many friends with people around.D. Going to see a movie on his own after school.【3】Which of the following expressions can be used on a student who often breaks school rules?A. A lone wolf.B. Raised by wolves.C. Wolf call.D. A wolf in sheep's clothing.【4】Where is it possible for us to find the passage above?A. A book for travel guide.B. A magazine on trade and business.C. A science report.D. A program for English learning.