题目

下列关于聚乙烯的说法正确的是( )A. 聚乙烯是通过加聚反应生成的B. 聚乙烯具有固定的元素组成，因而有固定的熔、沸点C. 聚乙烯塑料袋因有毒，故不能装食品D. 聚乙烯因性质稳定，故不易造成污染 答案：【答案】A【解析】聚乙烯是混合物，没有固定的熔、沸点，B项错误；聚乙烯塑料袋没有毒，能装食品，C项错误；聚乙烯会造成白色污染，D项错误。七选五How to Avoid Mistakes in the IELTS TestMany students, some with very good English skills, take the academic IELTS (International English Language Testing System) test and fail to achieve the score they expected or hoped for. In order to avoid this, it is important to have an understanding of what you need to do in each part of the exam and have some basic strategies. 1.Don’t give very short answersDon’t just answer "yes" or "no" to questions. The examiner needs to hear you speak, so always give extra information.For example, for part 1:Q: Do you have a big family?A: Yes, I do. I have my parents, and I also have three brothers and two sisters. My aunt lives with us as well. 2.It can be quite noisy in our house, but it’s still a lot of fun!3.It is important to extend your answers, but at the same time you must be answering the question or talking about things related to the topic. You won’t gain extra marks for talking for the sake of it, if it has nothing to do with what you have been asked!Listen carefullyAlways listen carefully to what the examiner asks you. Again, you aren’t be expected to be talking about something different to what you are asked.4.If you don’t understand a question or you don’t hear it, then ask the examiner to repeat it. There is nothing wrong with needing to do this a few times during the test.Talk for two minutesIt is OK to give extra information, so feel free to tell the examiner everything you can think about the topic. 5.You can plan what you say in the 1-minute preparation time and think of what extra information you can give.A. Keep to the topicB. Ask if you don’t understandC. Think carefully before speakD. There is no need to talk too much.E. So I would say that is quite a large family.F. But remember you need to speak fluently and clearly.G. In this article, I will provide you with speaking strategies.