Analysis of the composition of quicksand shows that there are four key ingredients—sand, obviously water, clay and salt. Together these materials form a structure resembling a house of cards, with large water-filled gaps between the sand particles, which are loosely glued in place by the clay. As long as it’s left alone, the structure remains stable. But as soon as it’s disturbed, by stepping on it, the clay changes from a jelly-like consistency to a runny liquid. The effect is the same as stirring a pot of yoghurt. Liquefying(溶解)the clay makes the quicksand about one million times runnier, and the whole house of cards comes tumbling down, with you inside it.

Very quickly, the sand sinks to the bottom and the water floats to the top. This is where the salt comes in. When there’s enough salt present, as soon as the clay particles liquefy, electrical charges make them begin to stick together to form bigger particles and these also settle with the sand. Quicksand is a mixture which looks like solid, but behaves more like a liquid.

Despite its murderous reputation, quicksand does not such people under and swallow them, although it can hold a person in firm grip. The human body is more buoyant(有浮力) in quicksand than in water, and sooner or later anyone trapped in it will float.

Unlike most liquids, quicksand’s viscosity, or “runniness” can suddenly change if it comes under pressure, for example under a human foot. The surface gives way and the victim quickly sinks in up to the knees, surrounded by an area of dirty things that turns semi-solid around its victim. Escaping from the quicksand’s grip(紧握) requires a large amount of force. Without something solid to pull at, people often find they are stuck fast. Pulling at one leg simply makes the other one sink further.

So how do you escape from quicksand’s control? Stay still and call for help. Staying still stops you sinking any further, until--with luck--help arrives on the scene. If no one appears and you need to draw yourself out, gently lie down on your back until your body is floating on the sand. Next, roll over onto your stomach and pull yourself forwards with your hands, so that you gradually “swim” towards firmer ground. It is a slow and dirty business, but it works.

This technique has one barrier: it goes against a very powerful human nature. Faced with danger in the open, nine out of ten stay on their feet so that they can run away, in which case it can worsen the situation.

1.Which ingredient of the quicksand make someone trapped in it stuck and stuck fast?

A. Sand B. Clay C. Water D. Salt

2.From the passage we can learn that ________

A. as long as you are strong enough, you can pull yourself up from quicksand on your own

B. clay glues sand particles loosely, which makes quicksand stable, unless it is disturbed

C. because anyone trapped in quicksand will float, there is little possibility of him dying

D. looking like solid ground, quicksand is actually liquid

3.If someone is trapped in quicksand, what should he do?

A. Remain calm and wave for help

B. Stand in quicksand and get ready to run away as quickly as possible

C. “Swimming” is one of the best choices he can use to escape

D. Once in quicksand, lie down on his stomach immediately and swim slowly to safety

4. What might be the best title of the passage?

A. A human killer--quicksand

B. How to escape from danger

C. An awful experience in quicksand

D. What to do if trapped in quicksand

完形填空,阅读下面短文,掌握其大意,从每题所给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。

Mr. Jackson was blind from birth. He owned a fruit ____ on a very busy street. ____he was visually disabled, he ran his business pretty handsomely. He could see nothing and he could only ____ the things within his reach. ____, he was able to handle it and was content with everything he had.

One day his son came to him. He told Mr. Jackson in ____ that he read in the newspaper of a __46__ who could operate on his eyes and allow him to see. The father and the son traveled to the doctor and paid for the ____.

After the operation, the doctor asked Mr. Jackson, “What is the first thing you are ____ to see when I take the bandages off?” He replied, “I really want to see my beautiful ____ on my stand!”

The doctor and the son ____Mr. Jackson down to the busy street where his fruit stand had been located for so many years. The doctor ____ unwrapped the bandages ____ he could lay his eyes on the beautiful fruit! Mr. Jackson was so full of ____ that he could finally see his life’s work—taking care of his fruit! After a few hours of ____ his beautiful fruit stand, he looked down the street both ways and saw there were quite a few fruit stands in both directions. He looked ____ the street and saw many other fruit stands. He spent so much time looking at other people’s fruit stands and ____ the competition that soon his own business ____.

From Mr. Jackson’s failure, we should know that everyone is a ___ individual with different fingerprints, DNA and thinking. What we need to do is just be ourselves and ____everyone else to be who they are. Mind our own business and we should never be afraid of ____.

1.A. company B. stand C. store D. centre

2.A. Because B. as C. When D. Although

3.A. feel B. remember C. observe D. describe

4.A. However B. Therefore C. Otherwise D. Besides

5.A. pride B. doubt C. surprise D. excitement

6.A. nurse B. doctor C. chemist D. surprise

7.A. operation B. information C. medicine D. service

8.A. nervous B. lucky C. afraid D. eager

9.A. flowers B. fruit C. vegetable D. clothing

10.A. sent B. followed C. accompanied D. invited

11.A. carefully B. suddenly C. curiously D. firmly

12.A. in case B. so that C. even if D. if only

13.A. regret B. courage C. joy D. relief

14.A. selling B. judging C. enjoying D. making

15.A. above B. across C. within D. through

16.A. preparing for B. focusing on C. taking up D. worrying about

17.A. improved B. appeared C. expanded D. failed

18.A. unique B. reliable C. perfect D. simple

19.A. force B. require C. allow D. persuade

20.A. change B. difference C. competition D. disability

Investing in yourself

Figuring out how to invest your money can be a difficult task. This is something that you will want to learn how to do.

1.Things that will improve your knowledge, skills or health are all great investments. However, before you start, you need to be clear about what you will gain out of doing all of these things.

You may think investing in yourself means investing in your education.2. There are some other things you can do as well as buying a gym membership or learning a new skill.

So what are some specific things you can do? 3.. Reading books can really expand your mind and allow you to learn different skills and gain knowledge. I’m talking about the books where you will actually learn a new skill, not fiction books. You can also take courses and attend seminars. These programs are taught by people with a high level of knowledge or skill. 4.. Only in this way can you avoid being fooled by some sales presentation. Moreover, investing in yourself is a safe way to keep your money. Although a savings account is seen as the most secure investment, that isn’t 100% safe. Even if you never experience your bank closing down, the return is little when inflation(通货膨胀) is taken into consideration.5.. But over time, they will show up in terms of your happiness level as well as your level of success.

A. This is just one way.

B. The benefits will stay with you.

C. If you aren’t a reader, you should start with that.

D. The more you do this, the more valuable you will be.

E. Of course, you need to do some research before investing.

F. The best way to invest your money is to invest it in yourself.

G. When you invest in yourself, you may not see gains right away.

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