At some automobile toll-collecting stations, a
thin metal wire sticks up from the road and
makes contact with cars before they reach the
toll collector.
What is the purpose of this wire?
1. To warn the drivers
2. To count the vehicles
3. To transfer positive particles to the automobile
4. To discharge the automobile
5. To transfer electrons to the automobile
The purpose of the wire at some automobile toll-collecting stations is to count the vehicles that pass through. This is option 2.
To get this answer, we can eliminate options 1, 3, 4, and 5 by understanding the function of the wire. The wire is not there to warn the drivers, transfer positive particles or electrons, or discharge the automobile. Instead, it is designed to make contact with the cars as they pass over it, and this contact is used to count the vehicles.