2017年6月25日托福听力机经小范围预测

2017年6月25日托福听力机经小范围预测

　　本文的资料是中华考试网托福频道为大家准备2017年6月25日听力机经小范围预测，

　　在大家考试之前会提供相关的备考资料，比如密押机经以及练习题等，大家可以认真分析一下，相信会帮助大家考试更加顺利。

　　1. What is the lecture mainly about?

　　(A) Ways to generate heat for nuclear fusion

　　(B) Differences between nuclear fission nuclear fusion

　　(C) A controversial theory regarding how to generate nuclear fusion

　　(D) The possibility of establishing sustained nuclear fusion

　　2. According to the students, what are three advantages of nuclear fusion over nuclear fission

　　Click on 3 answers.

　　(A) Nuclear fusion can use a fuel that is more easily obtained.

　　(B) Nuclear fusion can be achieved at lower temperatures.

　　(C) Nuclear fusion produces more energy.

　　(D) Nuclear fusion does not produce hazardous by-products.

　　(E) Nuclear fusion does not require as many natural resources.

　　3. Why does the professor mention isotopes of hydrogen?

　　(A) To correct a student's comment about how fusion takes place in stars

　　(B) To help answer a student's question about temperature requirements for fusion reactors

　　(C) To explain what happens to hydrogen atoms during fusion reactions

　　(D) To justify the need for superconducting magnets in nuclear fusion reactors

　　4. According to the professor, how will the ITER reactor differ from earlier experimental fusion reactors?

　　Click on 2 answers.

　　(A) It will be transportable to different locations.

　　(B) It will sustain nuclear reactions through heat that it generates on its own.

　　(C) It will heat the fuel mixture to a higher temperature.

　　(D) It will confine the plasma in a more energy-efficient way.

　　5. What does the professor say about the international effort to develop ITER?

　　(A) The participation of many countries may cause ITER to be delayed even more.

　　(B) The research orientation of ITER has encouraged international collaboration.

　　(C) ITER will make use of equipment made in many different countries.

　　(D) The lack of international cooperation on earlier fusion projects has hurt ITER.

　　6. What does the professor imply when he says this:

　　(A) He prefers to work on projects with more immediate results.

　　(B) He believes that research in the physical sciences requires strict time lines.

　　(C) He thinks it will take less time to develop ITER than most researchers expect.

　　(D) He is more skeptical about the future of nuclear fusion than most researchers are.