Solar energy is a long lasting source of energy,and it can (1).... almost anywhere.To generate solar energy,we only nedd solar cells and (2).... ! Solar cells can easily be installs on house (3)...... ,so we don' need any new space.Compared with orther renewable sources,they also possess many advantages:wind and water power rely on turbines which (4).... noisy,expensiveand which take up large space.Solar cells are totally silent and non-polluted.As they have no moving parts,they require little maintenance and have a long lifetime.
 1. A.be used     B.is used             C.be using          D.to be used
 2. A.the earth    B.the plant          C.the sun            D.the moon
 3. A.yards         B.roffs                 C.gardens           D.doors 
 4. A.is               B.be                   C.are                    D.was