如图,在方格纸上建立的平面直角坐标系中,将△ABO绕点O按顺时针方向旋转90°,得△A′B′O′,则点A′的坐标为( )
A:(3,1)
B:(3,2)
C:(2,3)
D:(1,3)
Over years,scientists have made a great________in the treatment of cancer.
地球自转产生了( )