Harriet is visiting David, who hurt himself when he fell off a ladder. Complete the conversation using can or a form of be able to. Sometimes there is more than one possible answer

Can and be able to (2)
Harriet is visiting David, who hurt himself when he fell off a ladder. Complete the conversation using can or a form of be able to. Sometimes there is more than one possible answer.
Harriet: Hello, David. I'm sorry I haven't (►) been able to come (come) and see you before. I've been really busy lately. How are you?
David: I'm OK, thanks. (1)  (I / walk) around now. The doctor says (2)  (I / go) back to work soon. It'll be nice (3)  (get) out again. I hate being stuck here like this. I haven't (4)  (do) anything interesting
Gợi ý: GIẢI THÍCH GIÚP EM Ạ