下列变化,是通过取代反应来实现的是
A.CH3CH2OH ─→CH3CHO
B.CH2=CH2─→ CH3-CH2Br
C.乙酸─→
D.氯乙烯─→聚氯乙烯
答案:C
_______ time and labor, cartoonists generally draw the hands of their characters with only 3 fingers and a thumb.
A.Save
B.Having saved
C.Saving
D.To save
市场追随者在竞争战略上应当()。
A.攻击市场领导者
B.向市场领导者挑战
C.跟随市场领导者
D.不做出任何竞争反应