21. —How did it_ __ that you made so many mistakes in your homework?
—I myself haven’t figured it out yet.
A. bring about B. come about C. come across D. occur to
22. — I hear that there was a terrible crash in the subway in Shanghai the other day.
—Yes, ______news came as ______shock to all of us.
A. the; the B. a; / C. the; a D. /; a
