——Do you think students should be allowed to do their homework with music on?
—— . If so, they can't concentrate on the study.
A:I agree
B:I think so
C:I disagree
D:I have no idea.
下列实验方案中,能证明氢氧化钠溶液与稀盐酸发生了化学反应的是( )
给农作物施磷肥的主要目的是为其提供( )
15∶18=10∶12