There are many people downstairs. What do you think _____

Mum, can I play football-No, unless your work____.

If metal is heated and then cooled very quickly, , by dipping in cold water, it will be very hard but will break easily.

My computer has gone wrong. It needs _______soon. — Why not have David _______ it Nobody can ifhe can’t.

Tom．Any idea where Mary is— She in thereading room．I sawher there just now．