问题
单项选择题
下图中所示的查询返回的记录是（）
A.不包含80分和90分
B.不包含80至90分数段
C.包含80至90分数段
D.所有的记录
答案
参考答案：D
解析：
逻辑运算符“NOT”的含义是当NOT连接的表达式为真时，表达式为假。题目中显示期末成绩查询条件为“NOT 80或NOT 90”，所以查询结果应该是所有的记录。
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下图中所示的查询返回的记录是（）
A.不包含80分和90分
B.不包含80至90分数段
C.包含80至90分数段
D.所有的记录
参考答案：D
解析：
逻辑运算符“NOT”的含义是当NOT连接的表达式为真时，表达式为假。题目中显示期末成绩查询条件为“NOT 80或NOT 90”，所以查询结果应该是所有的记录。
| 阅读理解。 根据短文内容，从下框的A---F选项中选出能概括每一段主题的最佳选项。 选项中有一项为多余选项。 | |
When speaking about renewable energy, we are talking about power which gets its energy from resources which will not be diminished from the use. Renewable energy is a substitute for the non-renewable energy of fossil fuel. 2. ( ) One fundamental advantage of renewable energy, and environmentalists' favorite reason to promote its use, is that there are no greenhouse gases or other pollutants that give out as there are with the burning of fossil fuels. Renewable energy, or solar, water and wind power, are certainly not new although they have received much attention recently because they will not cause pollution. Environmentally friendly power sources such as wind, solar and water power have been used in both developing and developed countries for a long time because they are cheap and clean, but they have yet to be used as a primary source of energy for any big urban area. 3. ( ) The generation of power from renewable energy sources has become somewhat more common in recent times as people have increasingly become aware of issues such as climate change due to fossil fuel byproducts and the political or social worries about nuclear power. There are numerous countries and non-profit, environmentally conscious organizations that are supporting the use of renewable energy. 4. ( ) The flow of renewable energy has to do with naturally occurring phenomena. Tides, sunlight, wind and heat are all created by geothermal events and all are sources of energy. Each of these sources of energy has unique characteristics related to where and how we can use them. 5. ( ) Most technology which transforms renewable energy into power which we can use is solar powered either directly or indirectly. The atmospheric system of the earth keeps balance so that the heat which spreads out into space is equal to the amount of radiation received from the sun. The quantity of energy contained in the atmosphere approximates the earth's climate. The bodies of water of the earth, or its hydrosphere, absorb much of the radiation which is received from the sun. And much of that absorbed radiation is in the lower latitudes surrounding the equator. |