—Excuse me, sir. Would you do me a favor?—Of course. What is it?—I ________ if you could tell me how to fill out this form. 

—I didn’t ask for the name list .why       on my desk?—I put it there just now in case you needed it.

It is well known to us all that a lot of rivers _______by factories.

The calculations, had they been done by hand, ______all practical value by the time they were finished.

 —I wonder what makes you a successful manager.—I ________ as a waiter for five years，which contributes a lot to my today’s work.