Bài 23 :
2. Do the crossword puzzle and complete the sentences.
(Chơi trò chơi ô chữ và hoàn thành các câu.)

Across:
1. Solar energy is __________ and it can be replaced easily.
2. Hydro energy is __________ because it requires dams.
3. Coal, oil and natural gas are non-renewable energy sources. Burning them is __________ to the environment.
Down:
4. The alternative sources of energy like the sun and wind are not only plentiful but also __________ and safe to use.
5. Wind energy is convenient and __________.
6. Coal is __________ and it can be replaced by renewable sources.
7. For many people living in rural areas, biogas is a __________ source of energy.
8. Nuclear energy can provide enough electricity for the world's needs, but it is __________.
Danh sách bình luận