11. Fossil fuels which are non-renewable pollute the air and cause air ____.
A. pollution B. solution C. contaminate D. consumption
12. Recycling provides a method of reducing the amount of waste materials that gets to the landfills - thus ____ it less probable for environmental pollution to take place.
A. making B. doing C. causing D. trying
13. If wastes are thrown ____, they can cause pollution in water, land and air.
A. inappropriately B. disappointingly C. eco-friendly D. favourably
14. Trees not only bring nature to urban areas, but they also help clean the air by absorbing pollutants, ____ oxygen, ____ water, and grow food.
A. to provide - to save B. to provide - save C. providing - saving D. provide - save
15. Air pollution is such a serious ____ that it has been a direct factor in the ____ of millions of people each year.
A. threat - death B. threat - deaths C. threaten - death D. threaten - deaths
16. Sometimes it's better not to buy something new, and buy it ____ instead.
A. used B. usable C. use D. useful
17. He asked the children ____ the river.
A. don't pollute B. if they don't pollute C. not to pollute D. not polluting
18. They asked me how many students ____ in the school.
A. there were B. were there C . there are D. are there
19. He told me that ____.
A. he would participate in the conservation campaign yesterday
B. he had participated in the conservation campaign the previous day
C. he participated in the conservation campaign the previous day
D. he has participated in the conservation campaign the previous day
20. He asked, “Why did she write the article on conservation?”
He asked why ____.
A. she had written the article on conservation B. she has written the article on conservation
C. she wrote the article on conservation D. did she write the article on conservation
