Question 32·Medium·Central Ideas and Details
In northern Chile’s Atacama Desert, rainfall rarely exceeds 1 millimeter per year, yet small coastal villages survive thanks to “fog catchers.” These simple devices consist of tall meshes stretched between poles on misty ridges. Moisture-laden fog drifts through the mesh, condenses into droplets, and trickles into gutters leading to storage tanks. Engineers visiting the region once dismissed fog catchers as quaint but inefficient. Current studies, however, reveal that a single 50-square-meter net can collect up to 400 liters of water on a humid morning—enough to irrigate crops and supply drinking water for dozens of households. As a result, environmental groups now promote fog catchers as a low-cost, sustainable solution for communities facing water scarcity.
According to the passage, why have environmental groups begun to promote fog catchers?
For "According to the passage" questions, go straight to the sentence that mentions the key subject (here, "environmental groups") and then read the sentence immediately before it to catch cause-and-effect links like "as a result." Paraphrase the stated reason in your own words, then choose the option that matches that paraphrase while eliminating choices that contradict the text or introduce details the passage never mentions.
Hints
Find where environmental groups are mentioned
Skim the passage and locate the sentence that talks about environmental groups. The reason you need is likely in that sentence or right before it.
Pay attention to cause-and-effect words
Notice the phrase "As a result" in the sentence about environmental groups. Ask yourself: a result of what? Look at the sentence immediately before it.
Identify the key new information before "As a result"
In the sentence before "As a result," what do the current studies show about fog catchers? Think about why that information might convince people to support them.
Check each choice against the passage
For each answer choice, ask: Does the passage clearly say this, or does it contradict the passage? Eliminate choices that add unsupported claims or misstate what the devices can do.
Step-by-step Explanation
Find the sentence about environmental groups
The passage says, “As a result, environmental groups now promote fog catchers as a low-cost, sustainable solution for communities facing water scarcity.” The phrase “As a result” signals that the reason appears immediately before this sentence.
Identify what caused that result
The previous sentence explains that current studies show “a single 50-square-meter net can collect up to 400 liters of water on a humid morning,” enough to irrigate crops and supply drinking water.
Match the cause to the best choice
Environmental groups began promoting fog catchers because research shows they can collect hundreds of liters of water, making them effective for helping communities facing water shortages. Therefore, the correct answer is: Because studies show a single net can collect hundreds of liters of water, helping relieve water scarcity.