– What colour is it? -
A:It's red.
B:It's a rabbit.
C:I hear a pig.
“早穿皮袄午穿纱,围着火炉吃西瓜”,反映的生活现象在 ( )
如图,截去正方体一角变成的多面体有____条棱.
影响城市空气质量的因素是( )