下列物质不属于有机物的是 [ ]
A．甲醛(HCHO)
B．葡萄糖(C6H12O6)
C．醋酸(CH3COOH)
D．碳酸(H2CO3)
答案：D
---I think students should have mobile phones to call their parents.
---___________. They often use them to play games instead.
A．I hope so
B．I don’t agree
C．No problem
D．Good idea.
下列主要影响因素中，( )决定供给价格弹性的大小。
A．商品本身用途的多用性B．消费者对某种商品的需求程度C．商品的替代品数目D．产品的成本状况
