Solar energy is a long lasting source of energy, and it can (31) ________ almost anywhere. To generate solar energy, we only need solar cells and (32) ________! Solar cells can easily be installed on house roofs, (33) ________ we don’t need any new space. Compared to other renewable sources, they also possess many advantages: wind and water power rely on turbines (34) ________ is noisy, expensive and which take up large space. Solar cells are totally silent and non-polluting. As they have no moving parts, they require (35) ________ maintenance and have a long lifetime.

31. A. be used             B. is used                     C. be using                  D. to be used

32. A. the earth            B. the planet                C. the sun                    D. the moon

33. A. and                   B. but                          C. or                            D. so

34. A. who                  B. which                      C. where                     D. when

35. A. little                  B. many                       C. few             D. any