You ______ be serious! You’re actually going to lend him money again？.

You can’t imagine that a well-behaved gentleman __________ be so rude to a lady.

Please remind your grandpa to take medicine on time, for a man of his age ____be very forgetful．

—Is John coming by train?—He should, but he     not. He likes driving his car, but I’m not quite sure.

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