LR Drill Set 5, Question 12
Building bridges requires complex considerations.(112 more words not shown)
Which one of the following(6 more words not shown)
- Alonger bridges generally(5 more words not shown)
- Bbridge engineers are(12 more words not shown)
- Cthe greater the(13 more words not shown)
- Dbridge engineers are(18 more words not shown)
- Ebridge engineers are(20 more words not shown)
Reading the argument
A shorter bridge needs fewer supports, but those supports have a harder job.
At the narrow part of the river, water moves faster and puts more stress on the piers. At a wider spot, the water puts less stress on each pier, but the bridge needs more piers to reach the other bank. We have a trade-off: fewer supports in tougher conditions or more supports in gentler conditions.
Can the narrow bridge still be safe?
Yes. The passage says engineers can reinforce the piers to handle the greater stress. But reinforcement adds expense, so shortening the bridge doesn't automatically save money overall.
What we’re looking for
We need to finish the passage while respecting both priorities. Safety comes first, and cost still matters once we consider how to make the bridge safe. I wouldn't announce that the shorter bridge wins just because it uses fewer piers, or that the longer one wins just because each pier needs less reinforcement. We need to weigh the extra costs against the savings. Let's see which answer keeps that trade-off rather than declaring a winner too soon.
Working the answers
- A
The longer bridge's piers face less stress, but the shorter bridge's piers can be reinforced. The passage explicitly says that reinforcement lets engineers ensure safety even under greater stress. It therefore doesn't establish that longer bridges are generally safer. The cost of achieving safety is the unresolved comparison.
- B
This sounds reasonable if we focus only on the expensive reinforcement at the narrow site. But more piers also cost money. What if avoiding those additional piers saves more than reinforcement costs? B gives a general preference for length without checking that balance. The passage supports considering the total expense, not a blanket preference for longer bridges.
- C
More stress would matter if the piers stayed the same. Here, however, engineers can change the supports to withstand it. A reinforced pier under greater stress can still support a safe bridge. C ignores the adjustment that the passage explicitly provides and doesn't capture the design choice involving safety and cost.
- D
Taking expense seriously doesn't mean abandoning every expensive safe bridge. The passage discusses choosing how and where to span a river; it never establishes a preference for building nothing. A costly bridge could still be worth building, especially if every safe design costs a lot.
- ECorrect
The shorter bridge brings a reinforcement expense, so engineers have a reason to avoid it unless other savings offset that expense. For example, suppose reinforcement adds $100,000 but using fewer piers saves $150,000. The shorter design could then make financial sense while remaining safe. If it saved only $40,000, that same reinforcement expense would count against it.
Those figures are illustrations, not facts about the project. They show why the qualification matters. E preserves the possibility that either length makes sense depending on the costs; B skips the cost balance and treats the longer design as the general winner.
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