TASK 3: Choose the best topic sentence.
1.
Solar-
powered cars are very expensive because of the high development cost of solar
batteries. In addition, the cells of the solar batteries can store only limited
amounts of energy. Therefore, solar cars are not practical for driving on long trips.
The biggest problem is the constant need to recharge the cells. This is especially
difficult when one drives on cloudy days and at night-time.
a) Solar-powered cars are expensive
b) There are many advantages and disadvantages of solar energy
c) The future practicality of solar cars depends on overcoming problems with
solar batteries
d) Solar batteries are the key to understanding how solar energy can be used to
drive cars