University should pave running trails

The university has about three miles of unpaved dirt running trails that pass through the forest near campus. I think there trails should be paved with cement. One reason for paving the trails would be to increase their safety. When it rains, the dirt turns to mud and becomes very slippery, so the runners who use them can slip and fall. Pavement would solve this problem. Also, paving would make the trails look nicer, which would encourage students to use them. Bumps in the trail would be smoothed out and weeds would be paved over, making the trail more attractive to runners.
Sincerely,
Sally Jacobs

The proposal is university should pave the dirt trails with cement because by doing this, university can make the trail less slip and the runners won't be falling. And also, they are hoping the pavement will make the trails look better and attract more runners.

The man thinks this is a terrible idea. Speaking of the reason, he thinks that running on hard surface frequently will not make the runners safer, because being exposed to hard surface will actually lead to injuries and harm to bones or joints. Besides, it won't attract more runners because the pavement will make the trails just like any other sidewalk. Students like to run on the dirt trail since it makes them feel like getting away from cities and running in the nature.

Perceptual Constancy

How an object affects our senses depends in part on external conditions, and these conditions are always changing. An object viewed from one angle presents a different shape to our eyes than when viewed from another angle; similarly, as the distance from which we view an object changes, the object will appear larger or smaller. In spite of this, even as conditions change and we see objects differently, we still recognize that they remain the same. This is what is known as perceptual constancy. If not for perceptual constancy, we might have difficulty recognizing familiar objects if we viewed them in a new and different context.

1. 解决一个问题的两个方案
2. 一个物体或方法的两种使用方法
3. 一个过程的两个步骤
4. 一个原因导致的两个现象
5. 一个后果产生的两个原因
6. 一个概念的两种定义

1.The professor is discussing two different definitions of money.
2.A broad definition of money is anything that can be used to make purchases with.
3.For example, people might give a taxi driver coins or bills, or even vegetables for a ride.
4.A narrower definition of money is something that must be accepted as payment, legal tender.
5.For example, a taxi driver must accept coins and bills, but he does not have to accept vegetables, because vegetables are not legal tender in the U.S.

The professor is talking about two different definitions of money. A broad definition of money is anything that can be used to make purchases with. For example, people might give a taxi driver coins or bills for a ride. If they don’t have coins or bills, they may even use vegetables as a form of money to purchase the service, I mean, the ride. A narrower definition of money is something that must be accepted as payment, in a more formal way, legal tender. For example, a taxi driver must accept coins and bills because they are legal tender in the U.S., however, he does not have to accept vegetables, because he is not required by the law to do this.