已知点A的坐标为（a，b），点A在第一象限，O为坐标原点，连接OA,将线段OA绕点O按逆时针方向旋转90°得OA₁，则点A₁的坐标为（  ）

义和团的“扶清灭洋”口号带有笼统排外性质，这是指义和团 （    ）

看句子，连线。

① How is your mother? ____     A. You are welcome.

② Thank you.____            B. No, I haven't.

③ Have you got enough food?____    C. I was in Shanghai.

④ What did you do lastSunday?____  D. We watched TV at home.

⑤ Where were you two daysago?____  E. Sheis very well.

图是卫星甲和卫星乙在某一时刻所覆盖的区域．其服务范围大小是（   ）