以下四种有机物的分子式皆为C4H10O:其中既能发生消去反应生成相应的烯烃,又能氧化生成相应醛的是
A.①②
B.只有②
C.②和③
D.③和④
答案:C
—Mike doesn't look happy. What's wrong with him?
—It seems that he has some trouble ______ that problem. [ ]
A. solve
B. solves
C. solving
D. to solve
催化剂在化学反应中所起的作用是( )
A.增加生成物的质量
B.加快其他反应物的化学反应速率
C.减慢其他反应物的化学反应速率
D.改变其他反应物的化学反应速率