题目内容

1. Can we predict earthquakes?
2. Can we control earthquakes?
To answer the first question, scientists are looking very closely at the most active fault systems in the country, such as the San Andreas Fault in California. A fault is a break between two sections of the earth's surface. These breaks between sections are the places where earthquakes occur.
Scientists look at the faults for changes which might show that an earthquake was about to occur. But it will probably be many years before we can predict earthquakes accurately and the control of earthquakes is even farther away.
Nevertheless, there have been some interesting developments in the field of controlling earthquakes. The most interesting development concerns the Rocky Mountain Arsenal earthquakes. Here water was pat into a layer of rocks 4,000 metres below the surface of the ground. Shortly after this injection of water, there was a small number of earthquakes. Scientists have decided that the water which was injected into the rocks worked like oil on each other. When the water" oiled" the fault, the fault became slippery and the energy of an earthquake was released.
Scientists are still experimenting at the site of these earthquakes. They have realized that there is a connection between the injection of the water and the earthquake activity. They have suggested that it might be possible to use this knowledge to prevent very big, destructive earthquakes, that is, scientists could inject some kind of fluid like water into faults and change one big earthquake into a number of small, harmless earthquakes.
Earthquake belts are ______.

A. maps that show where earthquakes are likely to occur
B. zones with a high probability of earthquakes
C. breaks between two sections of the earth's surface
D. the two layers of earth along a fault

查看答案
更多问题

按材料在建筑物中的功能分类,建筑材料可分为()。

A. 建筑结构材料、围护和隔绝材料、其他功能材料
B. 建筑结构材料、围护和隔绝材料、层合型材料、装饰材料
C. 装饰材料、复合材料、围护和隔绝材料、其他功能材料
D. 建筑结构材料、围护和隔绝材料、装饰材料、其他功能材料

对于案件中涉及国家秘密的,应向党委保密。()

A. 正确
B. 错误

【B5】

A. Despite of this
B. Therefore
C. However
D. As a result

证券公司应当于每个交易日()前向交易所报送当日各标的证券融资买入额、融资还款额、融资余额,以及融券卖出量、融券偿还量和融券余量等数据。

A. 9:30
B. 22:00
C. 1:30
D. 3:30

答案查题题库