Question 101·Medium·Inferences
Cities facing rising summer temperatures have accelerated tree-planting programs to mitigate urban heat. Fast-growing species provide shade within a few years but tend to live shorter lives and require more maintenance. A decade-long study by López et al. found that neighborhoods with a diverse mix of slower- and faster-growing trees sustained higher canopy coverage over time, even when budgets were limited, because losses in one group were offset by the other. Therefore, urban foresters seeking long-term cooling benefits should _____
Which choice most logically completes the text?
For SAT logical-completion questions, first mark signal words like "Therefore" or "Thus" that show the blank is a conclusion. Then, restate in your own words the key evidence just before the blank, focusing on what actually worked or mattered in the study or argument. Next, eliminate choices that (1) ignore that key evidence, (2) contradict it, or (3) introduce new ideas not mentioned. Finally, pick the option that directly matches both the evidence and the stated goal (here, long-term cooling and sustained canopy coverage), even if it uses slightly different wording.
Hints
Locate the key evidence
Focus on the sentence about the López et al. study. What specific type of neighborhood tree makeup led to higher canopy coverage over time?
Match the conclusion to the evidence
The word "Therefore" tells you the last blank should be a recommendation based on the study. Ask: what planting strategy does the study support for keeping canopy coverage high in the long term, especially with limited budgets?
Eliminate choices that contradict the passage
Look for answer choices that ignore or go against the idea that losses in one group were offset by the other. Any option that focuses on only one kind of tree or on delaying action should be suspicious.
Connect to the goal of "long-term cooling benefits"
Which option most clearly supports sustained shade and canopy coverage over many years, rather than just quick short-term shade or administrative convenience?
Step-by-step Explanation
Identify the purpose of the final sentence
The last sentence begins with "Therefore," which signals a conclusion or recommendation based on the information just given. Your job is to choose the option that states what urban foresters should do to get long-term cooling benefits, using the study’s results as support.
Restate the key findings of the study
The passage tells us:
- Fast-growing species: give shade quickly, but live shorter lives and need more maintenance.
- López et al. study: neighborhoods with a diverse mix of slower- and faster-growing trees had higher canopy coverage over time, even when budgets were limited, because losses in one group were offset by the other.
So, the evidence clearly favors diversity of growth rates for long-term canopy coverage under tight budgets.
Connect the study to the goal in the question
The goal stated is "long-term cooling benefits", which depend on sustained canopy coverage over time.
The study directly tells us what leads to sustained canopy coverage: a mix of slower- and faster-growing trees. So the correct completion should recommend a planting strategy that matches this idea.
Evaluate which choice matches the evidence and goal
Now check each option against the study’s finding:
- Any choice that focuses on only one type of tree (only fast-growing, only older/younger, etc.) clashes with the emphasis on a diverse mix.
- Any choice that suggests delaying or ignoring planting does not support long-term cooling.
The only option that uses the study’s evidence (diverse mix of growth rates) and directly supports long-term canopy coverage and cooling is:
D) prioritize planting a mix of species with different growth rates to balance quick shade with canopy longevity.