9. Hydro power is_________ because dams cannot be built in certain areas.A. limited B. unlimited C. abundant D. dangerous

38. Now scientists _________ new energy sources to protect the environment.A. develop B. develops C. is developing D. are developing

33. Where ___________? – I ___________ my lessons in the study.A. are you - am preparing B. you are – am preparing C. are you - prepares D. you are - prepare

36. The changing lifestyle of modern man ___________ our environment.A. polluting B. is polluting C. don’t pollute D. are polluting

28. What ___________ Kelvin doing? – He ___________ at my desk.A. do - does B. is - sits C. does - sits D. is – is sitting

30. Scientists ___________ a new vaccine against skin cancer.A. develops B. are develop C. are developing D. developing

20. We ___________a project of science at present.A. is doing B. are doing C. do D. does

39. I _________ for a present but I can’t find anything good.A. am look B. am looking C. look D. are looking

37. Now we _________ for a cheap, clean and efficient energy source.A. look B. are looking C. looks D. is looking

26. When he ___________in, I___________ in the kitchen.A. comes / am cooking B. come / am cookingC. is coming / am D. comes / are

34. On my way home, I ___________ to buy a bottle of fresh water.A. stop usually B. usually stop C. am usually stopping D. am stopping usually

23. The festival ___________at 8:30 a.m.A. starts B. is starting C. to start D. start

14. Do not use more _____ than what we need.A. wind B. food C. sunlight D. energy