What's Sandy doing?
A:Playing the piano
B:Playing computer games.
C:Watching TV.
制作洋葱表皮细胞临时装片和人的口腔表皮细胞临时装片时,应在玻片中央分别滴加( )
爸爸49岁,叔叔40岁,那么爸爸比叔叔年长多少岁?
about with of at in
图中反映的城市功能区是( )