—No,It's on the sofa.
A:Is the ruler in your schoolbag
B:Where is your ruler
C:What color is your schoolbag
D:Where are your rulers
如图所示,一艘炮艇沿长江由西向东快速行驶,在炮艇上发射炮弹射击北岸的目标.要击中目标,射击方向应( )