题目

Sandy didn’t have ______money for a bus ticket，_______she had to walk home in the rain． A．many；and  B．much；because C．any；so  D．some；but 答案：C如图，将放置于平面直角坐标系中的三角板AOB绕O点顺时针旋转90°得△A′OB′，已知∠AOB=60°，∠B=90°，OB=1，则B′的坐标为（ ）A．B．C．D．