问题
填空题
Questions 14-18
·Using the information in the text, complete each sentence 14-18, with a word or phrase from the list below.
·For each sentence (14-18), mark one letter (A-G) on the Answer Sheet.
·Do not mark any letter twice.
14. According to Dr. Score, lightning is caused by hail falling through ______.
15. The refrigerated rod served the same functions as ______.
16. Ice particles bouncing off hail falling through a cloud acquire ______.
17. In the paragraph four the word "duplicated" means ______.
18. According to S.E. Regnolds, there could be no lightning without ______.
- A. copy
- B. a positive charge
- C. a negative charge
- D. super cooled clouds
- E. falling hail clouds
- F. hail and super cooled clouds
- G. moisture particles
答案
参考答案：D
解析： 相关信息参看文章第1段第2句：“Dr．Scorer believes the cause is hail failing through supercooled clouds”(Dr．Scorer认为闪电是冰雹划过温度极低的云层而产生的)。