补全对话。 A: I'm anxious, because I 1 find my backpack. B: Really? 2 did you drop it? A: I think I 3 it during the concert. B: So it 4 still be in the symphony hall. Go there to have a look. By the way, 5 are you so anxious? A: Because I have a math test 6 algebra tomorrow. B: Oh, terrible. A: It's 7 that it counts 30% 8 the final exam. B: I'm 9 to hear that. A: 10 you have any ideas, please call me. B: OK. I will.