Question

source of freshwater
turning salt water into freshwater may seem like magic. but it’s not. many countries do it. today, few people do this to meet their water needs. but by 2025, 14 percent of us will lack freshwater. we will have to make more freshwater. so, desalination has a strong future.

desalination removes salt from water to make freshwater. people learned how to do this long ago. aristotle wrote about it in 20 bce. sailors turned salt water into drinking water in the 1770s. then methods got better during world war ii. soldiers in the desert needed water. in the 1950s, people found new ways to filter seawater. by the 1990s, many cities were making freshwater from the sea.

3 in the last 10 years, the use of desalination has grown. the largest projects are in saudi arabia, australia, algeria, and israel. in california, a new plant will soon serve the people of san diego. it will make 56 million gallons of freshwater each day!

4 as it is used more, desalination becomes more inexpensive. as its costs go down, desalination offers relief that can quench the needs of those in areas hit by drought.

in this sentence, what is the effect of the phrase quench the needs?

• it shows that desalination methods have changed.
• it stresses the importance of desalination.
• it shows how thirsty people are in drought - stricken areas.
• it stresses the importance of water storage.

Explanation:

To determine the effect of "quench the needs", analyze each option:

• The first option is incorrect as the phrase doesn't relate to method changes.
• The phrase "quench the needs" in the context of drought - hit areas and desalination's cost - reduction implies desalination can meet water needs, thus stressing its importance (matches the second option).
• The third option is wrong as the phrase isn't about people's thirst level but desalination's role.
• The fourth option is incorrect as the phrase has no relation to water storage.

Answer:

B. It stresses the importance of desalination.