Read the passage carefully, then choose the correct letter A, B, C, or D

Read the passage carefully, then choose the correct letter A, B, C, or D
Solar energy is a long lasting source of energy, and it can be used almost anywhere. To generate solar energy, we only need solar cells and the sun! Solar cells can easily be installed on house roofs, so we do not need any new space. Compared to other renewable sources, they also possess many advantages: wind and water power rely on turbines which are noisy, expensive and which take up large space. Solar cells are totally silent and non-polluting. As they have no moving parts, they require little maintenance and have a long lifetime.
31. What is the passage mainly about?
A. solar energy                B. the advantages of solar cells
C. renewable energies             D. the disadvantages of solar cells
32. Why don’t we need new space in order to use solar energy?
A. Because solar energy can be used anywhere    B. Because solar cells are small
C. Because solar cells can be installed on house roofs
D. Because solar energy is long lasting
33. What does the word “they” in line 4 refer to?
A. solar cells        B. advantages        C. renewable energies        D. turbines
34. What are the disadvantages of other renewable sources?
A. Wind and water power rely on turbines which are noisy, expensive and which take up large space
B. Wind and water power rely on turbines which are noisy, expensive
C. Wind and water power rely on turbines which take up large space
D. They are noisy, expensive and which take up large space
35. What is NOT listed in the passage as an advantage of solar cells?
A. They are non-polluting.    B. They are quiet. C. They have a long lifetime. D. They are cheap