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it everywhere. post the letter B. to have the letter posted C. to have posted the letter D. having posted the letter 9. Sorry,we don’ t allow ______in the lecture room. smoke D. to smoking is something wrong with this bicycle. It really needs _____ . repair C. be repaired repaired 11. I remember _____ him before,but I’ ve fotten where it was. A. to see have seen seen D. seen 12. — I have been knocking the door ,but no one answers. — Why not ____ at the back door? A. try knocking B. try to knock C. to try knocking try to knock