题干
Whenever he was asked why he was late for class,he would answer carelessly,always_______the same thing.
A：saying
B：said
C：to say
D：having said
答案(点此获取答案解析）
A
轴、
轴分别交于A、B两点，把△AOB绕点A顺时针旋转60°后得到△AO′B′,则点B′的坐标是（ ）