AIR QUALITY

 People need to breathe. If they don’t breathe, they (1) ______ die. But how clean is the air people breathe? If they breathe 2) ______ air, they will have breathing problems and become ill. Plants and animals need clean air too. A lot of the things (3) ______ our lives create harmful gases and (4) ______ the air dirty, like cars, motorbikes and factories. Dirty air is called “(5) ______ air”. Air pollution can also make our Earth warmer. The problem of air pollution started with burning of coal in homes and factories.

1. A. will   B. are   C. must      D. have to

2. A. clean  B. fresh  C. clear  D. dirty

3. A. at B. on C. in  D. of

4. A. make   B. get   C. give      D. do

5. A. pollute B. polluted C. polluting      D. pollutant