根据短文内容，从下边的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。
A . The different structure of blue holes.
B. Why scientists are interested in blue holes.
C. How a blue hole comes into being.
D. Blue holes exploring is becoming popular.
E. Rules to obey when diving into blue holes.
F. The general definition of a blue hole.______________
A blue hole is a flooded sea cave with a hole that opens up at the land's surface. These cave systems form in carbonate rock, often on islands. Some blue holes have very special rock formations and water chemistry. Far below sea level, they contain some of the harshest environments on Earth, with no oxygen and no light. Yet these areas are filled with life forms that have adapted to the extreme conditions.___________
Blue holes get their name from the color some have when seen from the air. The color is usually a reflection of the sky on the water. Blue holes are the result of erosion in which water breaks down rock. Rain falling thousands of years ago contained chemicals which slowly wore away at the limestone landmass. These holes later filled with sea water as the sea level changed. The rising and falling of sea levels and the mixture of salt and fresh water further wore away at these cave formations. ____________
These flooded cave systems can be found in the ocean, or they can be found inland. Ocean caves are affected by tides, so they always have water movement. But blue holes on land are very still. They have several layers of water, chemicals, and bacteria. The top layer of fresh water comes from rainfall. This layer acts like a cap on top of the layered mixture, and keeps out oxygen from the atmosphere. The fresh water floats on a denser layer of saltwater. Underneath this is a layer of poisonous hydrogen sulfide, produced by bacteria living in the water. Underneath this layer is anoxic seawater -- water that does not contain any oxygen.___________
Information gathered from these blue holes is helping scientists to increase their understanding of biology, archaeology and geology. But exploring these blue hole environments brings danger as well as discovery. Scientists are interested in these caves because oxygen-free conditions there are similar to those on Earth long ago, before oxygen existed on our planet. But there are many difficulties involved in diving into blue holes. ___________
One reason blue holes have not been fully explored is that they can be extremely dangerous. There are many safety rules that divers must follow to help ensure their survival. First, divers must have training and experience to swim in these caves. Divers who explore a cave for the first time must establish a thin rope called a guideline. This line helps them to safely enter and exit the cave without getting lost.
阅读下列应用文及相关信息，并按照要求匹配信息，将答案填涂在答题卷的相应位置。
下面文章中有5个段落需要添加首句（第1～5 题）。请从以下选项（A、B、C、D、E 和 F）中选出适合各段落的首句，并在答题纸上将该选项标号涂黑。选项中有一项是多余选项。
A. Get to know yourself.
B. Take care of your body.
C. Practice basic respect towards yourself.
D. Be honest with yourself and with others.
E. Think about what it means to respect someone.
F. Recognize when people disrespect you and take steps to stop it.
How to Respect Yourself
A lack of self-respect can prevent you from fulfilling your potential and developing healthy relationships. Here are some steps to help you know how to respect yourself. __________ The qualities that we respect vary from person to person, and the way we express it varies from culture to culture. Generally, we respect people who have more experience and are more accomplished than ourselves. But there is also a basic level of respect that most people will agree is a right, and does not need to be earned. So think about what it means to respect others. Here are some widely agreed-upon signals of respect: You don’t steal from, harm, or insult them; you are honest with them; you listen to what they say, consider their opinions, and avoid interrupting them.
__________ We often do things for ourselves that we would never dream of doing for someone we care about. Whatever you believe to be respectful, apply it to yourself. Don’t harm yourself. Don’t insult yourself. Don’t steal from yourself. Be honest with yourself. Develop your own opinions and don’t be afraid to stand by them.
__________ A person with self-respect doesn’t allow others to treat them badly, and would rather not be around someone who is disrespectful. This might seem obvious, but there are many times when we accept being treated badly. When someone doesn’t give you basic respect, you need to be able to say, in one way or another, “You just disrespected me and that’s not acceptable! If you don’t respect me, I won’t spend time with you any more.” Can you say that, and mean it?
Can you turn your back on someone who’s clearly shown that they don’t respect you? Once you do, you’ll feel your sense of self-respect go up. __________ When you make an effort to keep your body in good working order, you’ll not only feel better physically, but also feel a sense of pride. Respecting your body also means not insulting it for what it is, naturally. Make an effort to get fit and stay healthy. Focus on the things you can change and improve, and do them because it feels good.
__________ The more you know about yourself, the more you’ll see and appreciate how unique you really are. And you’ll respect yourself more. Discover your principles, personality, and talents. Stop waiting for other people’s approval and start developing your own standards.
Develop a unique and original way of expressing your opinions while at the same time being a good listener.
Travel tips that are no longer true
We all love an inside trip, but some of the classic tips for travelers no longer hold true.
1. Book a plane ticket far in advance to save money.
This myth may have been true back in the 1960s, when flights were less common than they are today. Back then, the demand for a flight would naturally increase as the date approached, there being few other options. According to recent studies, the best time to buy a domestic ticket was between six and seven weeks before.
2.
Don’t ignore the benefits of going straight to the hotel to negotiate (商谈) a good deal on a room. Many hotel chains offer rate guarantees and encourage customers to book directly. Hotels also frequently have discounts or some offers that third-party websites don’t know. Apart from this, hotels give the upgrades, not the booking agents.
3. Avoid street food.If this means standing up at a cheap street stall (摊位), then follow the crowd. Don’t sit down at a restaurant and spend four times more, on the simple assumption that it’s the only safe option. Can you see what’s going on in the kitchen?
4. Carry your money in a special pocket or pouch.
This is the fastest way to stand out from locals — who will have their money in a wallet or purse. Only take what you need when you leave your hotel room.
| A．When in Rome, do what the Romans do. |
| B．And make sure to put your wallet in a front pocket. |
| C．This is only true if you are buying products that are heavily taxed. |
| D．Let yourself relax in a warm room for one or two people in single beds. |
E. Check the updates on these tall tales (说大话) to save cash and add experience to your trip.
F. These days, many alternatives for the most popular routes mean that demand stays steady.
G. The best hotel prices are on travel websites.
. Since that time, we've provided people like you --- teachers, doctors, salespeople, full-time parents --- with a way of having a great time, challenging themselves and reconnecting with family and friends.
The non-stop routine of everyday life – answering e-mails, sitting in staff meetings ---- can have a dulling effect on people's senses. . Otherworld provides just such an opportunity. It is an experience participants cherish and remember for years afterwards．
Coming to Otherworld is like stepping into the pages of an adventure novel. You'll meet a host of characters, portrayed by our staff, who'll start bringing the world to life. Mysteries will begin to unfold around you. . You' ll see amazing sights and do things you never dreamed possible．
Suppose you were traveling to a foreign country. When you arrived, you might read a guidebook or visit a tourist booth to familiarize yourself with the laws and customs of the place you were visiting.. Before the weekend, you'll receive a handbook, explaining Otherworld’s customs and conventions. When you arrive at the weekend itself, there'll be a short briefing to review the handbook's contents.
Then you and your group are taken to the front door of the Inn at World's Edge. You'll see candles on each of the tables. A fire will burn in the fireplace. At many of the tables, people will sit talking, arguing, and laughing. These people are our staff volunteers. . But now they are all costumed and playing roles as citizens of the village of World's Edge.
| A．And at that moment, the adventure begins． |
| B．Otherworld Adventure Weekend starts in much the same way． |
| C．They are the same people who welcomed you and helped you unload bags． |
| D．Maybe some of the local people would talk to you, telling you about nearby attractions．． |
E. Otherworld was founded in 1992 with an idea: to give people an extraordinary adventure．
F. Therefore, everybody needs a relaxing weekend - a good adventure to refresh themselves．
G. As you and your friends work together to solve them, you'll find yourselves challenged in ways that are exciting, unexpected and fun．
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。选项中有两项为多余选项。Half a minute? A few seconds?
Google engineers have discovered that even 400 milliseconds-as short as the blink of an eye-is too long for most Internet users.
A millisecond is one thousandth of a second. People hardly notice such a small time difference, but it does cause them to stop searching, reported The New York Times.
Nowadays, millions of smart-phones and computers are constantly gathering and sending out information.you can get digital "traffic jams". Meanwhile, users are expecting faster and faster service.
Google found that if one website is 250 milliseconds slower than another website ,then people will visit it less often.Google said people do expect different things from different websites because they realize not all loading times are the same. For example ,a person will be more patient waiting for a video clip to load than for a search result.
Even so, four out of five online users will click away if a video takes too long to load. This makes “difficult for video websites to choose between the quality of pictures and fast loading times.
Pursuing a higher speed has always been part of the history of the Internet.
In the 1990s,when the World Wide Web first started to become popular,people called it the "World Wide Wait". But engineers managed to fight the problem with new inventions. They laid a lot of fiber optic cables for high-speed transmissions , they improved software so it would work more smoothly; they placed computer servers all around the world to be nearer to users; all this increased speed.
Nowadays we can enjoy much faster Internet ._ But they will need to keep fighting to keep up with the developing demands of internet users.
| A．internet is becoming faster and faster. |
| B．With so many people downloading maps, sports videos, news and restaurant recommendations, |
| C．Major search engines such as Google and Microsoft's Bing usually find search results in less than a second. |
| D．We can not expect a faster speed about the internet. |
E. This is why technology companies are now competing to be the fastest.
F. How long are you willing to wait for a webpage to open before you start to lose your patience?
G it was very crowded and slow;
Many facts suggest that children are overweight and the situation is getting worse, according to the doctors. .
Some people blame(责备) the fact that we are surrounded (包围) by shops selling unhealthy, fatty foods, such as fried chicken and ice cream, at low prices. , then probably children would buy less take-away food.
. I agree with this, because good eating habits begin early in life, long before children start to visit fast food shops. If parents often give their children fried chicken and chocolate rather than healthy food, they will go for sweet and salty foods, and children will find it hard to get rid of the habit.
There is a third reason for this situation. Children these days take very little exercise. They do not walk to school. When they get home, they sit in front of the television or their computers and play computer games. . What they need is to go outside and play active games or sports.
The above are the main reasons for this problem. , as well as forcing them away from fast food shops and bad eating habits.
| A．There is another argument that blames parents for allowing their children to become overweight |
| B．Adults are becoming fatter and unhealthier too |
| C．If there were fewer of these restaurants |
| D．Therefore we have to encourage young people to be more active |
E. Not only is this an unhealthy pastime (消遣), it also gives them time to eat more unhealthy food
F. I feel there are a number of reasons for this
G. It’s a good idea to allow children to eat what they choose