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问题 多项选择题

世界卫生组织西太区将人的生命过程分为哪三个阶段（）

A.人生幼年阶段

B.人生中年阶段

C.晚年生活质量阶段

D.人生准备阶段

E.人生保护阶段

答案

参考答案：C, D, E

解答题

若方程ax2+2x-1=0至少有一个正实数根，求实数a的取值范围．
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填空题

Questions 9-13


·You will hearfive speakers talking about advantages or disadvantages about cloning.
·For questions 9-13, choose from the list A-F which advantage or disadvantage they are talking about.
·Use the letters only once. There is one extra letter which you do not need to use.
9. Speaker 1: ______
10. Speaker 2: ______
11. Speaker 3: ______
12. Speaker 4: ______
13. Speaker 5: ______
  • A. The element of uncertainty
  • B. Reverse the aging process
  • C. Helping infertile couples
  • D. Potential benefits to modern medicine
  • E. Improving food supply
  • F. The potential for abuse
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