补全对话(每空一词) 。 A: Mum, I've lost my art book.Have you 1._____ it anywhere? B: Is it the book 2._____ a red cover? A: Yes, that's 3_____ ! Where did you 4._____ it B: Sorry, I 5._____ seen it 6._____ .7._____ you tried to look 8._____ it under your bed? Maybe you dropped (丢) it there. A: Oh! Here it 9._____ . 10._____ goodness!? B: You should 11._____ more careful from now on.? A: Yes, it won't happen (发生) 12 . _____.