___is it ____has made Peter___ he is today?
Please tell me the after service of the computer; I’m worried about a breakdown sometime.
—Jack can't concentrate on his lessons recently.—Yes, that might ____ why he did so badly in the last test.
They two free tickets to Australia, otherwise they’d never have been able to afford to go.
Not until they left school how much their teachers loved them and helped them.
This new kind of chemicals will help keep the air, soil and water________ from pollution.