coaster [ˈkoʊstə(r)]

例句:

• I've been on an emotional roller-coaster since I've been here.
  自从我到了这里，情绪就起伏不定。
  
• It's an aural and visual roller coaster ride.
  来自BBC
• The last few weeks have been a real roller coaster.
  过去的几个星期，形势真是变幻莫测。
  
• Over the last few years Japan's socialists have seen their electoral popularity take a roller-coaster ride.
  在过去的几年里，日本社会党在选民中的支持率忽高忽低。
  
• Some people want to go on the roller coaster.
  来自VOA
• That means the roller coaster on Wall Street continues.
  来自VOA