问题 选择题

2011年2月19日“国际化学年在中国”科普活动在中国科技馆正式启动.下列和化学有关的说法中不正确的是(  )

A.牙膏中含有甘油,起到保持湿润的作用;添加的二氧化硅则用于增强牙膏的摩擦作用和去污效果

B.化学家合成和分离了超过4500万种物质.化学合成和分离技术为信息技术、生物技术、航空航天技术等奠定了物质基础

C.科学家从石墨晶体中剥离出单层的石墨片制得了石墨烯是迄今发现的强度最大的高分子化合物

D.同位素示踪法、利用核磁共振技术检测化学反应的中间体等方法是研究化学反应历程的重要手段

答案

A、牙膏是最常用的日用化学品之一,牙膏的成分有活性物质、摩擦剂、保持牙膏湿润的甘油等物质.牙膏摩擦剂的主要成分有CaCO3、Al(OH)3、SiO2,甘油的水溶液有保湿润肤的作用,二氧化硅不与盐酸反应,也不溶于水,故A正确;  

B、化学合成和分离技术为信息技术、生物技术、航空航天技术等奠定了物质基础,故B正确;

C、石墨烯又称单层墨,它仅由一层碳原子组成,具有许多奇特的属性,包括极强的拉力,优良的导电性和导热性,硬度最大,但不是高分子化合物,是碳元素的单质,故C错误;

根据有机物的核磁共振氢谱中含有的峰值来判断有机物含有的氢的种数,并根据有机物的结构特点来书写结构简式.

D、同位素示踪法,利用放射性核素作为示踪剂对研究对象进行标记的微量分析方法,根据有机物的核磁共振氢谱中含有的峰值来判断有机物含有的氢的种数,并根据有机物的结构特点来书写结构简式.故正确;

故选C.

完形填空

第二节:以下是五位专家的建议。请匹配这些建议及对应的生活感想或经验介绍(A、B、C、D、E和F)。选项中有一项是多余选项。请将答案代号(A、B、C、D、E、F)写在答题卷61~65的相应位置上。

61.        You should watch where your weight accumulates. You can use the waist. to. hip ratio to find if there is too much fat around the middle. Belly fat is especially dangerous because it release free fatty acids directly to the liver, virtually flooding it with fat.

62.        If a particular food is important to you, eat it, but work it off. You should try to learn the art of compromise.

63.        At the same time. the three-for-one is relatively simple to use. Fat grams and calories are listed on almost all boxed, canned or packaged foods—you have only to read the label and follow the rule. A five-year-old patient of mine can do this.

64.        Drinking water is basic, and drinking enough of it is necessary. Patients are sometimes surprised that basic things work when they do them consistently.

65.          Consume antioxidant foods. They protect the cholesterol C胆固醇), from oxidative damage, which helps prevent damage to blood…vessel walls.

A. More than nine years ago I was 70 pounds overweight and wore a very big dress. I had tried different diets and lost weight only to gain it back. Finally a simple “three. for. one’’ fat rule worked for me:consuming no more than three grams 0f fat for every 100 calories per serving. Following the rule and eating only foods that contain less than 30 percent fat, I spent eight months getting down to a size seven, and I’ve kept the weight off for nine years.

B. And for foods that aren’t packaged, you rely on what we already know about them. Red meat, as well as dishes made or served with butter, gravy, cream sauce or cheese, are almost never less than 30 percent fat—so you just don’t eat them. On the other hand, some non-packed foods—all fruits and vegetables。except avocadoes and olives—always pass the test. So do most fish。but not when fried.

C. I like vegetables, which are rich in vitamins. Most foods containing vitamins C and E(such as sweet potatoes, tomatoes, spinach and broccoli)are low in calories and are known as antioxidants(抗氧化物质). They can help reduce the possibility to develop hardening the arteries(动脉).

D. I gain weight around the belly—what we call abdominal obesity, the worst kind. The tendency seems to be hereditary(遗传的), and it’s common among men. This problem increases the risk of a stroke or heart attack. A guide I use in estimating belly fat is the waist-to—hip ratio, or WHR. To find yours. divide the circumference(周围)of your waist by the circumference of your hips. Women with ratios above 0. 8 and men with ratios above 1.0 are at increased health risk.

E. My ways of keeping healthy are very simple, and they are among our everyday activities:eating healthy food and doing exercise. In addition. I manage to do those basic things, such as drinking water, sleeping well and eating less fat. Sometimes I do some of the other things I used to do in my life like walking for half an hour a day.

F. Although I've put on ten pounds. I'm healthy and in good shape. I eat food that’s good for me…but 1 work off Susan’s homemade brownies(巧克力蛋糕), for example. To offset these extra calories, 1 walk for an hour or more, three times a week…often with Susan. We’re both busy and this is one way we have some quiet time together. Equally important, it permits me to practice dieting’s fine art of compromise.

单项选择题