It's the library! So you_______ make any noise here.

--The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?--________ my students have a try?

-- Why didn’t you go to Mike’s birthday party yesterday?-- Well, I _____, but I forgot it.

—Could you please come to the museum with me this afternoon?—Sorry，I ________．I have to take a piano lesson at 2 pm．

— Bill, is the pink umbrella Anna’s?— No, it _____ be hers. Hers is purple.