_Could I go to the movie this Sunday, Dad? _ Yes, you_____. But you ______ come back before nine.

We can see light in his office. He___________ be in his office.

--- Will the new iphone cost a lot?--- I ________ think so. Apple’s products are usually expensive.

I talked for a long time, and in the end I_____ make her believe me. 

--- 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?