[originaltext] Your professor has asked me to talk to you today about the to

游客2024-05-09  21

问题  
Your professor has asked me to talk to you today about the topic that should be of real concern to civil engineers: the erosion of the US beaches. Let me start with some statistics. Did you know that 90% of the coast in this country is eroding, on the gulf of Mexico for instance, erosion averages 4 to 5 feet per year? Over the past 20 years, there has been all increase in building along the coast, even though geologists and environmentalists have been warning communities about problems like erosion. Someway, communities have tried to protect their buildings and roads and to build seawalls.
    However, geologists have found that such stabilizing structures actually speed up the destruction of the beaches. These beaches with seawalls, called stabilized beaches, are much narrower than beaches without them. You may wonder how seawalls speed up beach loss. The explanation is simple. If the flow of the beaches is gentle, the water energy is lessened as it washes up along the shore. It is reduced even more that returns to the sea so it doesn’t carry back much sand. On the other hand, when the water hits the nearly-vertical face of the seawall, it goes straight back to the sea with the full force of its energy and it carries back a great deal of sand. Because of the real risk of losing beaches, many geologists support a ban on all types of stabilizing construction on shorelines.

选项 A、Protecting roads along the shore.
B、Building on beaches with seawalls.
C、Adding sand to beaches with seawalls.
D、Stopping building seawalls.

答案 D

解析 后三项都与seawalls有关,而A项却与此无关,故可首先排除。B项和D项的意思相反,根据命题规律,这类选项中往往有一个是答案。再根据短文末句提到的Because of the real risk... on all types of stabilizing construction on shorelines可知,地理学家建议人们不要建海堤,故答案为D项。
转载请注明原文地址:https://tihaiku.com/zcyy/3590308.html
最新回复(0)