A giant helium(氦) balloon is telling residents of Paris how good or bad the air
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A giant helium（氦） balloon is telling residents of Paris how good or bad the air quality is．When it’s good, the balloon ----measuring 22 meters wide and 32 meters high---shines green．_________, it’s red．
A．Though terrible B．Whenever good
C．If worse D．When bad
试题答案
D
解析:
略