IV. Give the correct form of the words given to complete sentences.       1.   We should use them                             and try to find out                  ECONOMY                     alternative sources of power.       2.   Solar energy is                        , plentiful and clean.                            RENEW       3.   I think that solar energy can be an                               source of        ALTER                            energy in the near future.       4.   We should reduce the use of                          at home.                     ELECTRICAL       5.   It’s a clean source of energy. Sailboats couldn’t move without        POWERFUL                         this             .       6.   Waves will be used as an                     friendly source of energy.      ENVIRONMENT       7.   Limit car trips by relying on biking, walking, public                         TRANSPORT                                   .       8.   Solar power can be used to                              or cool our houses.     HOT       9.   Energy is used to                     a lot of electrical things.                    PRODUCT       10. There will be a                         of energy in the near future.              SHORT