题目

2015年8月12日23:30左右，天津滨海新区的一处集装箱码头发生爆炸，发生爆炸的是集装箱内的易燃易爆物品氰化钠，数量为700吨左右。 资料：氰化钠化学式为NaCN，白色结晶颗粒或粉末，易潮解，有微弱的苦杏仁气味。剧毒，皮肤伤口接触、吸入、吞食微量可中毒死亡。熔点563.7℃，沸点1496℃。易溶于水，易水解生成氰化氢，水溶液呈强碱性，是一种重要的化工原料， 用于电镀、冶金和有机合成医药、农药及金属处理方面。    （1）用离子方程式表示根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。What is the purpose of readig or studying? If you can't remember what you read or study,it will be a waste of time． 1.   One useful aid that does help you remember what you study is to have a specific purpose or reason for reading．Why does a clerk in a store go away when your reply to her offer to help is, "No, thank you．I'm just looking．"? Both you and she know that if you aren't sure what you want, you are not likely to find it．But suppose you say instead, "Yes, thank you．I want a pair of sun glasses．" She says, "Right this way, please.”It’s quite the same with your studying. If you choose a book, "just looking" for nothing in particular, you are likely to get just that—nothing． 2. Your reasons will vary; they will include reading or studying "to find out more about", "to understand the reasons for" and "to find out how"．3. Before you start to study, you say to yourself something like this, "I want to know why Stephen Vincent Benet happened to write about America"．Because you know why you are reading or studying, you relate the information to your purpose and remember it better．Reading is not one single activity. 4. As you read, you take in ideas rapidly and accurately．But at the same time you express your own ideas to yourself as you react to what you read．You have a kind of mental conversation with the author．This additional process of thinking about what you read includes evaluating it, relating it to what you already know, and using it for your own purposes 5. One part of critical reading, as you have discovered, is distinguishing between facts and opinions．Facts can be checked by evidence. Opinions are one's own personal reactions．Another part of critical reading is judging sources．Still another part is drawing accurate inferences．A. This is an effective studying way. B．In other words, a good reader is a critical reader．C．You remember better when you know what you' re reading．D. At least two important processes go on at the same time.　E．It is important for students to have a positive attitude to their study．F. But if you do know what you want, you are almost sure to get it.G．Perhaps you have already discovered some good ways to keep yourself from forgetting．