如图在光滑水平面上，视为质点、质量均为m=1㎏的小球a、b相距d=3m，若b球处于静止，a球以初速度v0=4m/s，沿ab连线向b球方向运动，假设a、b两球之间存在着相互作用的斥力，大小恒为F=2N，从b球运动开始，解答下列问题：
如图，△OAB绕点O逆时针旋转80°到△OCD的位置，已知∠AOB=45°，则∠AOD等于（ ）
A: Hello, Mike.
B: Hello, Lucy.
A: ____
B: I'm feeling better now.
B: He said I had got a bad cold.
B: No, I can't. I have to stay in bed for a few days.
B: Could you help me with my lessons when I am well?
A: Sure. ____
B: Thank you.
A. What's wrong with you?
B. I hope you'll be better soon.
C. Can you come to school today?
D. How are you today?
E. I'm sorry to hear that.
F. What did the doctor say?
G. Are you feeling better now?
