Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

Our demand for water is constantly increasing. Every year there are more and more people in the world. Factories turn out more and more products and (25) _______more and more water. We live in a world of water. But almost all of it - about 97% - is in the oceans. This water is too salty to be used for drinking, farming, and manufacturing. Only about 3% of the world's water is fresh. Most of this water is not easily available to man (26) _______it is locked in glaciers and icecaps.

There is as much water on earth today as there ever was or will ever be. Water is used and reused over again. It is never used up. Although the world as a whole has plenty of (27) _______ water, some regions have a water shortage. Rain does not fall evenly over the earth. Some regions are always too dry, and others too wet. A region that usually gets enough rain may suddenly have a serious (28) _______and another region may be flooded with too much rain.

25. A. need B. must C. should D. necessitate

26. A. so that B. because C. though D. even if

27. A. salty B. new C. clean D. fresh

28. A. flood B. drought C. famine D. abundance