剑雅4-听力-Test1

Section 4
Good day, ladies and gentlemen.

I have been asked today to talk to you about the urban landscape.

There are 2 major areas that I will focus on in my talk, how vegetation can have a significant effect on urban climate and how we can better plan our cities using trees to provide more comfortable environment for us to live in.

Trees can have a significant impact on our cities. They can make our city, as a whole, a bit less windy, or a bit more windy, if that's what you want. They can make it a bit cooler if it's a hot summer day in an Australia city, or they can make it a bit more humid if it's a dry inland city.

On the local scale, that is, a particular areas within the city, trees can make the local area more shady, cooler, more humid, and much less windy.

In fact, trees and planting of various kinds, can be used to make city streets actually less dangerous in particular areas.

How do trees do all that, you ask?

Well, the main difference between a tree and a building is that a tree has got an internal mechanism to keep temperature regulated.

It evaporates water through its leaves, and that means that the temperature of the leaves is never very far from our body's own temperature.

The temperature of a building surface on a hot sunny day can easily be 20 degrees more than our temperature.

Trees, on the other hand, remain cooler than buildings because they are sweat.
vegetation 植被 n.