根据对话内容，完成对话中所缺单词，每空一词。
A: Can you tell us what we can do to protect our environment, Bob?
B: Sure, Mr. Smith. Remember to turn off the light. It (1)________ electricity.
A: Yes. What else?
B: We can (2)________ bikes to school. There will be less air pollution.
A: Right. Do you take your own bags when you go shopping?
B: Oh, I always (3)________ to take one. I'll remember to do it from now on.
A: And you should use both (4)________ of paper.
B: All right.
A: Do you recycle soft drink cans?
B: Yes. I have been doing it for two years.
A: Great! The environment is really (5)_________ to us and we can do lots of things for it.
