单选题 It is postulated that population trends have an effect on economic fluctuations.
  • A. challenged
  • B. assumed
  • C. deducted
  • D. decreed


【正确答案】 B
【答案解析】postulate：假定，与assume(设想、假定)意思相近。challenge：挑战；deduct：减去；decree：颁布(法令、政令)。