单选题 The prevailing wind is the wind direction most often observed during a given time period. Wind speed is the rate at which the air moves past a {{U}}stationary{{/U}} object.
  • A. motionless
  • B. massive
  • C. flexible
  • D. noticeable
【正确答案】 A
【答案解析】stationary“固定的”。A项motionless“不动的”；B项massive“厚重的”；C项flexible“灵活的”；D项noticeable“显而易见的”。故应选A。