11. To keep the air unpolluted, people ought to use ____ energy to create electricity. (sun)
12. There have been many ____ in the field of electrical engineering.(innovate)
13. Televisions, dishwashers and freezers are electrical ____. (apply)
14. No doubt that there will be a great ______ of food for the world's population. (short)
15. If there is something wrong with the lights, ask an _____ to look at it. (electric)
16. An old friend of mine felt amazed at the prize for her efforts at ____ in her country. (conserve)
17. The campaign against air pollution was organized by a famous _____ activist. (environment)
18. She carries a gun in her bag for personal ____. (protect)
19. Energy ____ is a problem all over the world. (conserve)
20. As it hasn't rained for months, there has been a serious____ of fresh water. (short)
11. solar
12. innovations
13. appliances
14. shortage
15. electrician
16. conservation
17. environmental
18. protection
19. conservation
20. shortage
