______ does your mother have _______ dinner?
A:What; to
B:What; for
C:How; for
D:How; at
现有银、铜、铁三种金属,某研究小组的同学为探究银、铜、铁的金属活动性顺序,设计了如图实验:
正面是____、侧面是____、上面是____
下列各句中,没有语病且语意明确的一项是( )