WE ARE WORRIED ABOUT THE _________ OF THE FRESH WATER FOR THE WORL...

20. We are worried about the _________ of the fresh water for the world’s population.

A. short

B. shortage

C. shorten

D. shortening

Choose the, word or phrase (A. B, C or D) that best fits the blank space

in the following passage:

Are you looking for a cheap, clean, effective (21)_________ of power that doesn’t cause

pollution or waste natural resources? Look no further than solar energy (22)_________

our Sun.

This power could be provided by the Sun. One percent of the solar energy that reaches

the Earth is enough to provide power for the (23) _________ population.

Many countries are already using solar energy. Solar panels are placed on the roofs of a

house and the Sun’s energy is used (24) _________ water. The energy can be stored for a

number of days; so on (25)_________ days you can use solar energy, too.