---George, how can you prove the earth is round?---I can’t, sir. ______, I never said it was.
-This dress was last year’s style. -I think it still looks perfect____ it has gone out this year.
-What do you think of my answer to the questions? -Sorry. What’s that? I______ about something else.
The pupils hurried to the classroom______ the bell rang.
Yesterday I was just to go out _____ someone telephoned me.
A boy with two dogs_____ when the earthquake rocked the city.