I.

21. B ( Almost all our energy comes from oil, coal, and natural gas. We call them fossil fuels )

22. A ( We can use energy from the sun, the wind, and the water )

23. D ( The sun supplies all the energy ... of the planet )

24. C ( plentiful = abundant = dồi dào )

II.

25. F ( Nowadays, television becomes very popular )

26. F ( Both old and young people enjoy watching it very much )

27. T ( Television stations also broadcast many interesting programs such as sports, music, cartoons, wilk life....etc )

28. T ( At present, people can enjoy a live program on TV )

E.

I.

29. will be having ( Thì tương lai tiếp diễn )

30. must be done ( Câu bị động ở dạng động từ khuyết thiếu )

31. will be buying ( Thì tương lai tiếp diễn )

32. will be used ( Câu bị đọng ở thì tương lai đơn )

II.

33. Mai used to cry when she was young.

34. We will reduce the use of electricity to save our energy.

21b

22a

23a

24c

25F

26F

27T

28T

29. will be having

30. will be do

31. will be buying

32. will be used

33. Mai used to cry when she was young

34. We will reduce our energy to save the use of electricity