据质谱图分析知某烷烃的相对分子质量为86,其核磁共振氢谱图有4个峰,峰面积比为6:4:3:1,则其结构简式为 ( )
My friend showed me round the town, ______ was very kind of him.
They use computers to keep the traffic _______ smoothly.
If you leave the club, you will not be_____back in .
What I need is_____ book that contains ______ABC of oil painting.
Jenny nearly missed the flight______ doing too much shopping.