You can go to the 24-hour shop ___________ you want.
A:whoever
B:whatever
C:whenever
D:however
肺泡外缠绕着丰富的毛细血管,这有利于( )
下面每个图形都是由9个小正方形组成的,其中各有4个小正方形是有阴影的,( )是轴对称图形。