根据对话情景，填入恰当的单词。 A: Are you online ? B: Yes, I am reading a letter. A: How (1) ______ do you use the Internet? B: I use it almost every day, but I only use it to check my (2) ______ to see if there are letters from my pen pal. You use the Internet a lot, don't you? A: Yes, I use it to do some (3) ______. I buy a lot of things at the lowest prices. B: It sounds (4) ______. So, you're online many hours a day? A: Yes. I like to do that. It makes me feel good. B: Do you think the Internet is very (5) ______ in our daily lives? A: Yes, I think so. It seems that we can't live without it. But there are some (6) ______, too. B: For example? A: A lot of the information you find online is not true. So you must be very careful. B: I see. Thanks for your advice.