A:Did your grandma learn English?
B:Did your grandma learn Chinese?
C:Did your grandpa learn English?
体育课时,同学们对“铅球”的制作材料进行讨论,有的同学认为“铅球”是铁制的,并从实验室借来吸铁石吸一下,“吸一下”这一过程属于科学探究中的( )
—That's quite a long time. There must be too many people waiting in line.
下列物质按氧化物、酸、碱、盐顺序排列的是( )