下列物质中,分子里的所有原子不可能在同一平面上的是( )
A.乙炔
B.苯甲醛
C.异戊二烯
D.苯乙烯(CH2=CH—C6H5)
答案:C
仓储管理方法的______是管理理念现代化的具体体现。
— The book isn't easy for Jack to understand, is it?
— ____. His foreign language is far better than expected.[ ]
A. No, it isn't
B. I'm afraid not
C. I don't think so
D. Yes, it is