题目

“纳米材料”是粒子直径为1～100 nm（纳米）的材料，纳米碳就是其中的一种。若将纳米碳均匀地分散到蒸馏水中，所形成的分散系（） ①是溶液 ②是胶体 ③能产生丁达尔效应 ④能透过滤纸 ⑤不能透过滤纸⑥静置后，会析出黑色沉淀 A . ①④⑥ B . ②③④ C . ②③⑤ D . ②③④⑥ 答案：BNow I’d like to talk to you about your final exam. The exam will be held next Thursday, the last day of the exam week. Remember to bring two or three pens in case you run out of ink. And unlike the midterm exam, this test will not include multiple --- choice questions; it will consist entirely of essays(文章). You’ll have to answer three of the five essay questions. The exam will be comprehensive (全面的), which means you’ll be responsible for all of the subject matters we covered in class this term, I would suggest you review your midterm exam as well as textbooks and your class notes. The final exam will count as 50 percent of your grade of the course. The research project (项目) will count as 20 percent and the midterm exam 30 percent. I’ll be in my office almost all day next Tuesday. If you run into any problems, please drop in. Good luck to you and I’ll see you on Tuesday.【1】 When will the final exam take place?A. On Tuesday B. On a WednesdayC. On a Thursday D. On a Friday【2】What will be included in the exam?A. There will be only multiple-choice questions.B. The exam will contain both multiple-choice and essay questions.C. The exam will have an oral and a written section.D. There will be only essay questions.【3】Why does the teacher call the exam comprehensive?A. It will be easy to understand.B. Students will be tested on all the material discussed in class.C. It will cover topics from a wide variety of subjects.D. Students must complete all parts of it.【4】The underlined phrase run into probably means .A. go intoB. meet somebody unexpectedlyC. come up against something with forceD. come across【5】When was this talk most likely given?A. During the first week of class B. During midterm weekC. On the last day of class D. On the last day of exam week