问题
选择题
既可用来鉴别甲烷与乙烯，又可除去甲烷中混有乙烯的最佳方法是（ ）
A．通入酸性高锰酸钾溶液中
B．通入足量溴水中
C．一定条件下通入H2
D．点燃
答案
答案：B
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既可用来鉴别甲烷与乙烯，又可除去甲烷中混有乙烯的最佳方法是（ ）
A．通入酸性高锰酸钾溶液中
B．通入足量溴水中
C．一定条件下通入H2
D．点燃
答案：B
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| My friends and I had just finished lunch at a hotel when it started to pour 1 . When it became lighter, I decided to get my car, which was 2 at my office three streets away. My friends argued that I shouldn't go, mainly because I was seven months pregnant then. I assured them that I'd be very 3 . I walked out of the 4 and started making my way to the car. At the traffic junction, a van stopped and the passenger got off with an umbrella. Before I knew what was happening, he walked right beside me and told me he'd escort(护送) me to my 5 . I was very embarrassed and declined(辞谢), but he was very 6 . During our 7 , he kept telling me to walk slower, as the ground was 8 . When we got to the car park, I 9 him and we parted ways. I did not get his 10 and may not even recognise him now. Did he 11 stop for me? I'll never know. So how did I pay it forward? I was at home when I 12 two Indian construction workers walking in the heavy rain. They were probably on their way to the construction 13 near my estate, which was a long walk in. I went out and passed them an umbrella. I told them they should take the umbrella and 14 it. They were very grateful and like me, probably wondered why a 15 was offering such kindness. | ||||
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