搜题请搜索小程序“爱下问搜题”
问题 单项选择题

传导速度最慢的是

A．K+外流
B．Ca2+内流和K+外流
C．Na+内流
D．Ca2+缓慢内流
E．Na+和Ca2+内流

答案

参考答案：C

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
查看答案
选择题

将化学知识用到生产、生活中，是学习化学的目的之一．下列做法中正确的是（　　）

A．家用电器着火，立即用水灭火

B．用水经常冲洗自行车以防止生锈

C．炒菜时油锅着火，立即盖上锅盖

D．用烧碱改良酸性土壤
查看答案