根据对话内容，从方框中选出能填入空白处的最佳选项，补全对话。

A：Hello，Mike! What’s the time?
B：       
A：Where’s Bob? I can’t find him.
B：I don’t think he can come.
A：       
B：He has to look after his sister.
A：       
B：She doesn’t feel well.
A：       Did she go to see the doctor?
B：Yes.
A：     
B：The doctor said nothing serious，but she has to rest.