PrepTest 111, Section 3, Question 9
A running track with a hard surface makes(42 more words not shown)
Which one of the following,(14 more words not shown)
- ADry running conditions(8 more words not shown)
- BIn general, taller(10 more words not shown)
- CHard tracks enhance(18 more words not shown)
- DThe tracks at(21 more words not shown)
- ETo remain in(15 more words not shown)
Reading the argument
Think about running on a firm surface versus sinking into sand. That gives me a way to picture the author's explanation: on the softer surface, getting the foot off the ground may take longer. On the harder one, the foot spends less time in contact with the ground.
The passage acknowledges a disadvantage of the hard surface: shorter steps. But it says the shorter contact time still makes the runner faster under dry conditions. I can follow that proposed explanation without knowing all the mechanics of running.
What we’re looking for
Now the question asks for evidence that this explanation is only partial. We don't need to deny that hard tracks make runners faster or that contact time helps explain it. I'd look for another reason hard tracks improve speed, or another reason soft tracks slow a runner down. The point is to show that contact time isn't the whole story.
Working the answers
- A
This concerns where dry conditions can be guaranteed. The explanation is already limited to dry conditions, so it doesn't need those conditions to hold everywhere. A gives no additional reason that a hard surface produces greater speed than a soft one when conditions are dry.
- B
Taller runners having longer steps doesn't explain a difference between running surfaces. The same runner can use either track, and the question is why changing the surface changes speed. B doesn't connect the height difference to that comparison.
- CCorrect
Better posture that reduces wind resistance is another way the hard track increases speed. That's different from keeping the foot in contact with the ground for less time. Both benefits could operate together, so the author's explanation could be right as far as it goes while still leaving out this additional contribution.
- D
Thin air at high altitude might matter to fast times, but D doesn't tell us that hard and soft tracks differ in altitude. We need a further explanation of why the hard surface is faster, not a fact about where some record performances happened. Without the link to surface type, D doesn't fill out this explanation.
- E
Different maintenance procedures don't establish a difference in runners' speed beyond the one described. Either surface could receive the care it needs. E tells us how the tracks are maintained, not another way their surfaces affect running.
More Weaken questions
Learn the LSAT our way
Our platform drills Weaken questions at your level and adjusts as you improve.