Tom, you ____ leave all your clothes on the floor like this.

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

With the help of the new technology, you __ e-mail your friends by mobile phone.

(2013·四川，5)—Why are your eyes so red？You________have slept well last night.—Yeah，I stayed up late writing a report.

(2013·北京东城二次联考)—________ you interrupt now？Can't you see I'm on the phone?—Sorry，sir，but it's urgent.