根据情景内容，在空白处填入合适的单词。
A: Hello, Mike! What are you (1)_________?
B: Hi, Tim! I’m repairing my bike.
A: Oh, it’s an old bike. It’s not worth repairing. Why(2)_________ buy a new one?
B: I don’t (3)________ with you. In my opinion, repairing is a good way to save resource.
A: (4)_________ great. After all, we are facing energy problems.
B: Yes. Everyone should get involved in saving energy for a better world.
A: Couldn’t agree (5)________. Let me help you repair the bike.
B: Thanks a lot.