Question 70·Easy·Central Ideas and Details
Ecologist Marisol Chen monitored a city park for three years and discovered that planting clusters of native wildflowers increased the number of visiting pollinators—bees, butterflies, and hoverflies—by nearly 60 percent. Chen argues that because these insects help fertilize surrounding trees and shrubs, city planners should integrate native wildflower patches into other urban green spaces to boost overall ecosystem health.
Which choice best states the main idea of the text?
For main idea questions, first paraphrase the passage in your own words, focusing on (1) the key result or idea and (2) any conclusion or recommendation that follows from it. Then quickly scan the choices and eliminate any that (a) add details or claims not in the passage, (b) are much stronger than what’s stated (words like “always,” “cannot,” “proved”), or (c) focus on a minor detail instead of the overall point. The correct answer will closely match your paraphrase and stay within the limits of what the text actually says.
Hints
Use both sentences, not just one
Reread the passage and ask: What result did Chen find in her study, and what does she argue city planners should do because of that result?
Watch for extra or extreme claims
Check each answer for words like “cannot survive,” “proved,” or statements about what planners have already done. Does the passage actually say those things, or just something weaker or different?
Connect evidence to conclusion
The main idea should connect the increase in pollinators to Chen’s recommendation for urban green spaces. Which option includes both the observed increase and the goal of improving ecosystem health?
Step-by-step Explanation
Understand Chen’s finding
Focus on the first sentence: Chen monitored a city park for three years and found that planting native wildflowers increased pollinators (bees, butterflies, hoverflies) by nearly 60 percent. So one key part of the main idea is that native wildflowers lead to many more pollinators in the park.
Understand Chen’s argument or recommendation
Now look at the second sentence: Chen argues that because these insects help fertilize surrounding trees and shrubs, city planners should integrate native wildflower patches into other urban green spaces to boost overall ecosystem health. The other key part of the main idea is her proposal to use wildflower patches in cities to improve ecosystem health.
Combine the finding and the argument into one main idea
A good main-idea answer must capture both:
- The evidence: planting native wildflowers greatly increases pollinator numbers.
- The conclusion/recommendation: planners should use these wildflower patches in urban areas to support healthier ecosystems. It should not add new claims (like stating something “cannot survive” or has “already” happened) that the passage never mentions.
Match the combined main idea to the best answer choice
Now compare the choices:
- Eliminate any choice that says something stronger than the passage (like “cannot survive” or “proved X is the most important”) or that changes the time frame (saying something has already been done when Chen just says it should be done).
- The only choice that accurately combines the increase in pollinators with the potential improvement of city ecosystems, without adding extra claims, is C) Introducing native wildflowers to urban parks can significantly raise pollinator numbers and may improve the health of city ecosystems.