题目内容
B. What
C. That
D. As
黄冈小状元解决问题天天练系列答案
三点一测快乐周计划系列答案Directions: Read the following text and choose the most suitable heading from A-F for each paragraph．There is one extra heading which you do not need.
| A．Causes of overusing fluoride | B．Negative effects of fluoride |
| C．Safe use of fluoride | D．The expert’s background information |
| E．No need to worry about fluoride poisoning | |
| F．Solutions to improper use of fluoride | |
I have heard that fluoride can help stop dental decay, but I recently read that it is poisonous．Which of these is true? How can children use fluoride safely?
This question is answered by Dr Marcia M．Rich who practises general dentistry in Newholt．She is also a lecturer at the University and a writer for the monthly magazine Your Dentist Cares．
My answer to the first question is to stress that fluoride works well and is safe when users follow instructions．Young children have a tendency to swallow toothpaste, which is why they should only have a tiny amount of fluoride toothpaste on their toothbrush．If this simple measure is taken, parents can be confident that children will be protected against tooth decay, and come to no harm.
Almost all medicines have an adverse effect－or even be deadly－if they are not taken as directed．So you are right－fluoride can be poisonous if it is swallowed in very large quantities．It is for the reason that fluoride supplements can only be obtained on prescription from the doctor or dentist．Please be assured that fluoride overdoses are rare－in fact, I have never heard of any fatal incidents related to fluoride poisoning.
Scientific studies have shown that fluoride can help to prevent cavities as long as it is used correctly．If fluoride is abused, there is a risk of illness or even deaths in extreme cases．If a deadly amount of fluoride is taken, immediate first-aid could save a life．A person who has swallowed a large amount of fluoride will probably start vomiting．If not, the patient should be given milk or antacid and taken to the nearest hospital for emergency treatment.
Taking too much fluoride while teeth are growing can lead to a condition called dental fluorosis．The most likely cause is the swallowing of fluoride toothpastes by young children．It can also be caused by inappropriate use of fluoride drop or other fluoride supplements, for example when fluoride is already is already present in drinking water．
根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中的两项为多途选项。
What is a big dream ? (1) Or , is a big dream something that provides only entertainment? Children dream big dreams, but there are three barriers to realizing dreams. They often kill them before they ever have a chance to grow.
The Self
Immediately following the birth of a big dream, a negative self-talk takes over and gives all the reasons why it cannot happen. This inside voice is the ego(自我). It’s there for protecting and should be listened to. (2) Most people are influenced by the inside voice. That’s why only a handful of people make their dream come true.
(3)
Family and friends are a lot like the ego. They want to protect those they love, so they will often list all the reasons why the big dreams won’t come true. Sometimes, family and friends destroy dreams of those they love most, out of their own fear of being left behind.
The World
If one gets past the first two barriers, one has to face the world. (4) In the past, big dreamers were locked up and sometimes even killed when they were shown to the world. Fortunately, in most of the world today, big dreamers just get laughed at.
The way to realize a big dream is with confidence and action. When children have confidence and then take action, they will be ready to accept any failure. The truth is that every great dreamer whose dreams have never seen the light of success knows failure well.(5)
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A．Family and Friends |
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B．How Big Dreams Die |
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C．Does a big dream show one’s future ? |
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D．They simply fail until they succeed. |
E. It is the last and the most terrible barrier.
F. Sometimes it is right, but more often it is wrong
G. And their big dream is to be a rock star or a famous artist.
Electric cars are dirty. In fact, not only are they dirty, they might even be more dirty than their gasoline-powered cousins.
People in California love to talk about “zero-emissions（排放）vehicles”, but people in California seem to be clueless about where electricity comes from. Power plants most all use fire to make it. Apart from the few people who have their roofs covered with solar cells, we get our electricity from generators（发电机）. Generators are fueled by something--usually coal, oil, but also by heat generated in nuclear power plants. There are a few wind farms and geothermal（地热） plants as well, but by far we get electricity mainly by burning something.
In other words, those "zero-emissions" cars are likely coal-burning cars. Because the coal is burned somewhere else, it looks clean. It is not true. It's as if the California Greens are covering their eyes—“If I can't see it, it's not happening.” Gasoline is an incredibly efficient way to power a vehicle; a gallon of gas has a lot of energy in it. But when you take that gas（or another fuel）and first use it to make electricity, you waste a nice part of that energy, mostly in the form of wasted heat--at the generator, through the transmission lines, etc.
A gallon of gas may drive your car 25 miles. But the electricity you get from that gallon of gas won't get you nearly as far -- so electric cars burn more fuel than gasoline-powered ones. If our electricity came mostly from wind or geothermal, or solar, then an electric car truly would be clean. But for political, technical, and economic reasons, we don't use much of those energy sources.
In addition, electric cars' batteries which are poisonous for a long time will eventually end up in a landfill. And finally, when cars are the polluters, the pollution is spread across all the roads. When it's a power plant, though，all the junk is in one place. Nature is very good at cleaning up when things are not too concentrated, but it takes a lot longer when all the garbage is in one spot.
1.What’s the main idea of the passages?
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A．Electric cars aren’t actually clean. |
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B．Electric cars are zero-emissions vehicles. |
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C．Zero-emissions vehicles are popular. |
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D．Gasoline-powered cars are more efficient. |
2.Which of the following words can replace “be clueless about” in Paragraph 2?
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A．Be familiar with． |
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B．Be curious about． |
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C．Fail to understand． |
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D．Show their interest in． |
3.The electricity we get from a gallon of gas may make our car run _________.
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A．at least 25 miles |
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B．more than 25 miles |
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C．as far as 25 miles |
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D．less than 25 miles |
4.In the author’s opinion, compared with cars using gas, electric cars are more __________.
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A．environmentally-friendly |
B．expensive |
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C．efficient |
D．harmful |
5.It can be inferred from the passage that __________.
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A．electric cars' batteries are poisonous for a long time |
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B．now electric cars are used more than their gasoline-powered cousins |
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C．zero-emissions vehicles should be chosen to protect our environment |
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D．electric cars are not clean in that we get electricity mainly by burning something |