20. 根据对话内容和汉语提示，用适当的表达完成对话。 A: Where is Jim? He isn't at school today. B: I (认为他不能) come to school today. A: Why not? B: He has to (呆在家) and look after his mother. A: (怎么了) with his mother? B: She (得了重感冒) yesterday. A: I'm sorry to hear that. Did she (看医生)? B: Yes. The doctor said she had to lie down and rest (几天). A: I hope she (快点儿好起来). Then are you free after school? B: Yes. Why? A: Let's go to see him and take the homework to him. B: That's a good idea.