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.