—Why are your eyes so red? You _______ have slept well last night.—Yeah, I stayed up late writing a report.

You’d better put on a heavy coat.Sometimes it________be very cold here at night.

—Where did you get this book?—I picked it up from a second-hand bookshop if you ______ know.

–Look at that girl! Is it Susan? --No, it _______ be her. She has gone back to her hometown.

The boys are going to have fun          the pictures.