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.Which ingredient of the quicksand make someone trapped in it stuck and stuck fast?
| A．Sand | B．Clay | C．Water | D．Salt |
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 |
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 |
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 |
In the Caucasus region of Russia, nearly 50 out of every 100,000 people live to celebrate their 100th birthday, and many don’t stop at 100! By comparison, in America only 3 people in 100,000 reach 100. But these Russian old people aren’t alone. The Pakistanis, who live high in the Himalaya Mountains, and the Ecuadorans of the Andes Mountains seem to share the secret of long life, too.
These people remain healthy in body and spirit despite the passage of time. While many older persons in industrial societies become weak and ill in their 60s and 70s, some Caucasians aged 100 to 140, work in the fields beside their great-great-grandchildren. Even the idea of aging is foreign to them. When asked “at what age does youth end?”most of these old people had no answer. Several replied, “Well, perhaps at age 80.”
What accounts for this ability to survive to such old age, and to survive so well？First of all, hard physical work is a way of life for all of these long-lived people. They begin their long days of physical labor as children and never seem to stop. For example, Mr . Rustam Mamedov is 142 years of age. His wife is 116 years old. They have been married for 90 years. Mr. Mamedov has no intention of retiring from his life as a farmer. “Why？What else would I do？”he asks. All these people get healthful rewards from the environment in which they work. They all come from mountainous regions. They live and work at elevations of 1,660 to 1,000 meters above sea level. The air has less oxygen and is pollution-free. This reduced-oxygen environment makes the heart and blood vessel(血管) system stronger.
Another factor that may contribute to the good health of these people is theirisolation. To a great extent, they are separated from the pressures and worries of industrial society. Inherited factors also play some role. Most of the longest-lived people had parents and grandparents who also reached veryold ages. Good family genes may, therefore, be one factorin living longer.The example of Mr. and Mrs. Mamedov implies that some Caucasians aged 100to 140____.
| A．become weak and hopeless |
| B．are too old to work in the fields |
| C．benefit from physical work |
| D．are still working in the fields |
What is the main way of life for all of these long-lived people?
| A．Retiring from their lives as farmers. |
| B．Having been married for 90 years. |
| C．Hard physical work. |
| D．Having no intentions. |
Which of the following factors isn’t helpful to people’s health and long life?
| A．Clean mountain air. | B．Daily hard work. |
| C．Good genes | D．Stress and pressure. |
NOT all memories are sweet. Some people spend all their lives trying to forget bad experiences. Violence and traffic accidents can leave people with terrible physical and emotional scars. Often they relive these experiences in nightmares.
Now American researchers think they are close to developing a pill, which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce ,or possibly erase(抹去),the effect of painful memories.
In November, experts tested a drug on people in the US and France. The drug stops the body releasing chemicals that fix memories in the brain. So far the research has suggested that only the emotional effects of memories may be reduced, not that the memories are erased.
The research has caused a great deal of argument. Some think it is a bad idea, While others support it.
Supporters say it could lead to pills that prevent or treat soldiers' troubling memories after war. They say that there are many people who suffer from terrible memories.
"Some memories can ruin people's lives . They come back to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions," said Roger Pitman, a professor of psychiatry at Harvard Medical School. "This could relieve a lot of that suffering."
But those who are against the research say that changing memories is very dangerous because memories give us our identity (特质). They also help us all avoid the mistakes of the past.
"All of us can think of bad events in our lives that were horrible at the time but make us who we are. I'm not sure we want to wipe those memories out, "said Rebecca Dresser, a medical ethicist.The passage is mainly about.
| A．a new medical invention |
| B．a new research on the pill |
| C．a way of erasing painful memories |
| D．an argument about the research on the pill |
The drug tested on people can.
| A．cause the brain to fix memories |
| B．stop people remembering bad experiences |
| C．prevent body producing certain chemicals |
| D．Wipe out the emotional effects of memories |
We can infer from the passage that.
| A．people doubt the effects of the pills |
| B．the pill will stop people's bad experiences |
| C．taking the pill will do harm to people's health |
| D．the pill has probably been produced in America |
Which of the following does Rebecca Dresser agree with?
| A．Some memories can ruin people's lives. |
| B．People want to get rid of bad memories. |
| C．Experiencing bad events makes us different from others. |
| D．The pill will reduce people's sufferings from bad memories. |
I came to study in the United States a year ago. Yet, I did not know the real American society until I was injured in a car accident because after the car accident I had to see a doctor---- and go to court(法庭).
After the accident, my roommate called a doctor for me. I was very grateful and determined to repay him one day. But the next day, he asked me to pay him $200 for what he had done. I was astonished. He had good reason to charge me, he said. And if I wanted to collect money from the person who was responsible for my injury. I’d have to have a good lawyer. And only a good doctor can help me get a good lawyer. Now that he had helped me find a good doctor, it was only fair that I should pay him.
But every time I want to see doctor, I had to wait about 50 minutes. He would see two or three patients at the same time, and often stop treating one so as to see another. Yet he charged me $115 each time. The final examination report consisted of ten lines and it cost me $215.
My lawyer was all smiles the first time we met. But after that he avoided seeing me at all. He knew very well the other party was responsible for the accident, yet he hardly did anything. He simply waited to collect his money. He was so irresponsible that I decided to dismiss him. And he made pay him $770.
Now I had to act as my own lawyer. Due to my inexperience, I told the insurance(保险) company the date I was leaving American. Knowing that, they played for time,….. and I left without getting a cent.
My experience taught me two things about America: firstly, in a country like America money is everything. It is more important than friendship, honor or professional morality（职业道德）. Secondly foreigners are still being treated unfairly. So when we talk about America, we should see both its good and bad sides.The author’s roommate offered to help him because ------------.
| A．he felt sorry for the author |
| B．he thought it was a chance to make some money |
| C．he knew the doctor was a very good one |
| D．he wanted the author to have a good lawyer |
The word “charge” in this passage means ----------.
| A．be responsible | B． accuse | C．ask as a price | D．claim |
Both the doctor and the lawyer in the passage are very ----------.
| A．friendly | B．greedy | C．professional | D．busy |
What conclusion can you draw from the story?
| A．Going to court is something very common in America |
| B．One must very careful while driving a car |
| C．There are more bad sides in America than good sides |
| D．Money is more important than other things in America |
Do you like to eat out? Do you like to eat quickly? Do you like inexpensive food? Some people go to fast-food restaurants for these reasons. In the past, people usually went to diners（小餐馆）for these reasons. In fact, many people in the States still go to diners today for the same reasons.
A man named Walter Scott had the first “diner” in 1872. It wasn’t a real diner. It was only a food cart. People on the street walked up to the cart to buy food. These carts served late-night workers who wanted a cup of coffee and a late-night meal. The meal was a sandwich or boiled eggs. In 1887, Samuel Jones built the first diner big enough to allow the customers to come inside. However, they did not sit down. Later, people built diners with counters and stools, and people sat down while they ate.
Before long, many diners stayed open around the clock. In other words, people were able to eat in diner at any time. Diners changed in other ways, too. The original menu of sandwiches and coffee became bigger. It included soup, favorite dishes, and a breakfast menu. In addition, diners soon became permanent buildings. They were no longer carts on wheels.
Diners today look similar to the diners of the early 1900s. They are usually buildings with large windows. Inside, the diners have shining counters with stools, booths, and tables and chairs. People can eat all three meals in a modern diner.
Today, many people eat in fast-food restaurants such as McDonald’s and Burger King. However, the diner remains an American tradition, and thousands of people still enjoy eating there. It was popular a century ago, and it is still popular today.A man named Walter Scott had the first “diner” in 1872. Why is the word “diner” in quotation marks(引号)？
| A．Because it is spelled differently from “ dinner” |
| B．Because the first diner was not what it is now |
| C．Because diner was a new word |
| D．Because it is a special kind of restaurant |
According to paragraph 3, diners changed in __________
| A．Two ways | B．three ways | C．four ways | D．five ways |
Which of the following is NOT true according to the passage?
| A．Diners existed before a fast-food restaurant |
| B．The menu included more food than sandwiches and coffee |
| C．Burger King is a fast-food restaurant |
| D．Sandwiches became bigger |
The main idea of the passage is that ______________.
| A． The diner is a traditional , popular place to eat in the United States |
| B． Samuel Johns built the first diner big enough to allow the customers to come inside |
| C． American diners serve many types of food 24 hours a day to their customers |
| D． Diners are different from fast-food restaurants in many ways |
I hear many parents saying that their teenage children are rebellion（反叛的）. I wish it were so. At your age you ought to be growing away from your parents. You should be learning to stand on your own two feet. But take a good look at the present rebellion. It seems that teenagers are all taking the same way of showing that they degree with their parents. Instead of striking out bravely on their own, most of them are trying to seize at one another’s hands for safety.
They say they want to dress as they please. But they all wear the same clothes. They set off in new directions in music. But somehow reason for thinking or acting in thus-and-such a way is that the crowd is doing it. They have come out of their cocoon(蚕茧) -----into a larger cocoon.
It has become harder and harder for a teenager to stand up against the popularity wave and to go his or her own way. Industry has firmly opened up a teenage market. These days every teenager can learn from newspapers and TV what a teenager should have and be. And many of today’s parents have come to award（奖励） high narks for the popularity of their children. All this adds up to great difficulty for the teenager who wants to find his or her own path.
But the difficulty is worth getting over. The path is worth following. You may want to listen to classical music instead of going to a party. You may want to collect rocks when everyone else is collecting records. You may have some thoughts that you don’t care to share at once with your classmates. Well, go to it. Find yourself. Be yourself. Popularity will come-----with the people who respect you for who you are. That’s the only kind of popularity that really counts.The writer’s purpose in writing this passage is to tell_______.
| A．readers how to be popular in the world |
| B．parents how to control and guide their children |
| C．teenagers how to learn to decide things for themselves |
| D．people how to understand and respect each other |
According to the writer, many teenagers think they are brave enough to act on their own, but, in fact, most of them______.
| A．are not sure of themselves |
| B．have much difficulty in understanding each other |
| C．dare not do things |
| D．are very much afraid of getting lost |
During the teenage years, one should learn to_____.
| A．become different from others in as many ways as possible |
| B．find one’s real self |
| C．get into the right reason and become popular |
| D．rebel against parents |