Listen and read the text. Complete each sentence with ONE word. (Nghe và đọc văn bản. Hoàn thành mỗi câu với MỘT từ.)
1. … fuels are limited, and they cause pollution.
2. Solar energy is … because the sun never stops producing sunlight.
3. They install giant wind … to get much more power all at once.
4. Our planet will be … if we stop using fossil fuels.
5. There is no … to solar energy and wind power.