—Can I pay the bill by check? —Sorry, sir．But it is the management rules of our hotel that payment     be made in cash．

It is strange that the small boy _________ work out such a difficult exercise, which is even hard to settle for adults.

 It is required in our school that lights in students’ rooms ______ off by 11o’clock.

How I wish I _____ the army then. I would have become a soldier.

—How much of the foreign expert’s speech have you understood?—Almost nothing. I wish I ________ harder at English.