Rose, you       leave your school things on the floor like this. Keep your room clean and tidy.

--- 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?

Doctor Wang      at seven o’clock for the conference, but she didn’t turn up. 

When he was there, he ________ go to that coffee shop at the corner after work every day.

---Fifty dollars for such a T-shirt！You_____ be joking！--- I’m serious. It’s made of silk.