The air pollution is serious, ________ we must try our best to reduce it.
A. so B. or C. if
--The river used to be clean. How does it become dirty?
-- There are many factories ________ waste water into it.
A. pouring B. pour C. poured
-- ________ Why don’t you clean your room?
-- Sorry, I’ll do it right away.
A. Take it easy.
B. What a mess!
C. Don’t worry.
Turn down your radio. Too much noise does great harm________ your ears.
A. for B. on C. to
-- When did you buy the car?
-- I ________ it for nearly two years.
A. have had B. have bought C. bought
-- The traffic in large cities is terrible and people drive fast.
-- ________ I don’t love it.
A. All right.
B. So it is.
C. It doesn’t matter.
