Fill in each numbered blank ONE suitable word. Write your answers in the space provided

Question IX. Fill in each numbered blank ONE suitable word. Write your answers
in the space provided.(20pts)
Solar energy is a long lasting source of energy which can be used
(1)_____anywhere. To generate solar energy, we only need solar cells and the sun!
Solar cells can easily be installed on house (2)______, so no new space is needed and
each user can quietly generate their own (3)______. Compared to other renewable
sources, they also possess many advantages. Wind and water power (4)______on

turbines which are noisy, expensive and easy to break down. Solar cells are totally
silent (5)_____ non-polluting. As they have no moving parts, they require little
maintenance and have a long lifetime.
(6)_________, solar energy also has some disadvantages. We can only generate
solar energy (7)_________daytime because the system depends on sunlight. Besides,
solar cells require large area to work effectively. The main disadvantage of solar
energy is (8)____________ it costs about twice as much as traditional sources such as
coal, oil, and gas. This is (9)___________ solar cells are expensive. Scientists are
hoping that the costs of solar cells will reduce as more and more people see the
advantages of this environmentally (10) ______source of energy.