听录音,补写下列对话所缺的单词,每空一词。 Sue: Hey, John! Where were you at 3: 30? John: I was at the hair salon. I was ____________ a ____________. Where were you at 5: 00? I went to the library. You weren't there. Sue: At 5: 00, I was ____________ ____________ a bus. We were ____________ a ____________ ____________at 3: 30.