—How did your mathematics exam go？—I thought I           ，but in fact I fell behind in the class.

After her son’s death, the old lady _____ sit at the window, deep in thought．

Don’t turn off the computer before closing all programs     you could have problems

I ran all the way to school yesterday, otherwise I        late for the annual talent show.

 ---- There’s no light on.   ---- They ________ be at home.