Nina is clever but kind of lazy. If she ___harder next term, she ___ better grades. 

 --What         if you don't finish your work on time?  -- Mrs. Brown will be very angry.

_____ you have _____ homework to do every day?

—What were you doing at this time yesterday?—We _______ in the classroom. 

Mark Twain ______ school and began to work at the age of twelve.