题目内容
The rare animals would die ________ if men were allowed to shoot as many as they wished.
- A.out
- B.up
- C.down
- D.away
The goal of earthquake prediction is to give early enough warning. The U.S. Geological Survey conducts and supports research on the likelihood of future earthquakes. Scientists estimate earthquake probabilities in two ways: by studying the history of large earthquakes in a special area and the rate at which strain(拉力)accumulates(积累)in the rock.
Scientists study the past frequency of large earthquakes in order to determine the future likelihood of similar large shocks. For example scientists researched the large earthquakes in the San Francisco Bay region during the 75 years between 1836 and 1911. For the next 68 years, no earthquakes of magnitude (震级) 6 or large occurred in the region. Beginning with a magnitude 6 shock in 1979, the earthquakes in the region increased dramatically; between 1979 and 1989, there were four magnitude 6 or greater earthquakes, including a magnitude 7.1 earthquake. So scientists estimated that the probability of a magnitude 6.8 or larger earthquake occurring during the next 30 years in the region is about 67 percent.
Another way to predict earthquakes is to study how fast strain accumulates. When plate movements build the strain in rocks to a critical level, like pulling a rubber band too tight, the rocks will suddenly break and slip to a new position. Scientists measure how much strain accumulates along a fault (断层) each year, how much time has passed since the last earthquake, and how much strain was released in the last earthquake. This information is used to calculate the time required for the accumulating strain to build to the level that results in an earthquake. This simple model is so complicated that such detailed information about faults is rare. In the United States, only the San Andreas Fault System has adequate records for using this prediction method.
Scientific understanding of earthquakes is of vital importance to the Nation. As the population increases, expanding urban development and construction encroach (侵蚀) upon areas susceptible(易受影响的) to earthquakes. With a greater understanding of the causes and effects of earthquakes, we may be able to reduce damage and loss of life from this destruction.
【小题1】What does the passage mainly talk about?
A.What an earthquake is like. |
B.How to predict earthquakes. |
C.Where earthquakes often happen. |
D.When a fault is formed. |
A.do research on the past frequency of large earthquakes |
B.estimate the magnitude of similar earthquakes |
C.forecast the possibilities of similar earthquakes |
D.judge the specific location of future earthquakes |
A.There were four magnitude 6 earthquakes in the San Francisco Bay region between1979 and1989. |
B.The accumulating strain of the fault to a certain level results in the earthquake. |
C.About 68 years after 1911, no earthquakes occurred in the San Francisco Bay region. |
D.The fast increasing population on the earth is the main cause of the earthquake. |
A.The material of rocks. |
B.The existing time span of the rocks. |
C.The plate movements around the rocks. |
D.The amount of strain released in the last earthquake. |
A.has a greater understanding of the causes and effects of earthquakes |
B.stores much more information about the history of large earthquakes |
C.offers the potential for doing research on the faults where strain accumulates |
D.illustrates specifically how rocks along a fault are formed |
NASA has opened the door to the next generation of space discovery by announcing great plans for a base for humans to live on the surface of the moon forever.
The project to build a base on the moon will begin soon after 2020, with astronauts living there within four years.
The project comes after several excellent scientists and environmentalists asked humans to look beyond Earth to ensure the survival of the species (物种).
Eventually, the moon will be a base for humans to explore the solar system and one day land on Mars.
NASA began planning for the first moon landing since 1972 when George Bush, the US president, announced his new plan for space exploration four years ago.
NASA has already talked about the design of the Orion spacecraft that will replace the old space shuttle fleet in 2010.
The plan for the moon base, however, is the first detailed explanation of how NASA intends to prepare for the first manned exploration of deep space and a possible Mars mission within 30 years.
Scientists also believe that the south pole on the moon contain rich natural gases such as the rare helium-3 that could be used as fuel for the generation of nuclear power. Besides, teams of astronauts living there for six months at a time would mine for hydrogen and oxygen to make water and possibly rocket fuel.
【小题1】When was the plan to explore space first announced according to the passage?
A.In 1972. | B.In 1950. | C.In 1968. | D.In 2020. |
A.to protect Earth | B.to explore deep space |
C.to finish Mars mission | D.to show how powerful the USA is |
A.hydrogen | B.food | C.oxygen | D.water |
A.the USA’s new plan for space exploration |
B.how to build a base on the moon |
C.why to ensure the survival of the species |
D.where to get new natural resources |
My bike was a three-speed English “racer”, purchased during my second year in college in November 1964 for $44. Most of the money was earned by myself in my spare time, but I had to get my mother to help me out a little. At that time, bikes were rare on a college campus. My reason for getting a bicycle was a little strange. A friend of mine convinced me to take a summer job selling door-to-door and suggested that I should use a bicycle to travel between houses. The job didn’t work out, but the idea was in my brain.
That fall, I borrowed another student’s bike and rode 45 miles on the first day, but his bike soon had a flat(瘪了的轮胎) which he didn’t like fixing. So I had to buy one. I immediately started using mine almost every day. Before getting the bike, I sometimes walked 28 miles to my parents’ house. Now the bike gave me a quicker method, but my first trip took four hours due to strong headwinds that had me fight for every foot. Once I made a trip of 100 miles in one day. I decided to use the bike to go camping in the Smokies. During the trip, I recognized the need for handlebars and more gears, so I bought a ten-speed after just one year though I loved this bike.
The first bike “hung around” for a couple of years, and then I gave it to my sister’s kids who let it become part of their lives.
【小题1】What can we learn from the passage?
A.His mother gave him some money when he bought the first bike. |
B.The first bike was a gift from his mother. |
C.He bought the first bike for racing. |
D.He wanted to buy a bike because all his classmates had one. |
A.often helped his friend do business |
B.also worked in a factory |
C.had part-time jobs in his spare time |
D.had to make money to pay for his tuition |
A.selling door-to-door |
B.buying a bike of his own |
C.borrowing a bike from others |
D.earning money by working |
A.unnecessary | B.very useful |
C.a lifelong tool | D.too troublesome |
Many people say pennies are not worth saving. After all, a penny is only worth a cent. But one unusual penny turned out to be worth a lot more when a coin collector paid $1.7 million for it earlier this month.
The coin is one of a kind. It is the only penny that the Denver mint(铸币厂) made out of copper, instead of steel, in 1943. Because it is unique, it is also very valuable. No penny has ever sold for so much money.
The Changing Penny
The Lincoln penny first appeared in 1909. For 34 years, the one-cent coin was made out of copper. Then, in 1943, the penny changed. World War II was going on, and copper was needed for equipment. So for one year, pennies were made out of steel instead. At least most of them were.
Only a few coins were made out of unused copper. There are three main mints, or places where coins are made, in the United States. Of the known copper pennies from 1943, twelve were made in the Philadephia mint, and five were made in the San Francisco mint. Only one was made in the Denver mint.
Nobody knows for sure why a copper penny was made at the Denver mint in 1943, coin dealers Andy Skrabalak told Time for Kids. “There is a rumor that a mint employee made the coin in the middle of the night.”
A Special Set
The coin collector who bought the $1.7 million penny wants to remain unknown. But the reason for the trade is known. He already had two copper pennies from 1943 – one from the San Francisco mint and one from the Philadephia mint. To complete the set, he needed the Denver penny. The three coins will go on display at a coin exhibition in Tampa, Florida.
The collector who sold the penny is also keeping his name a secret. It took four years to convince him to give up the rare coin. Now that he has finally donating all of the money to charity.
1.Why is the Lincoln penny worth over one million dollars?
A. Because it has a history of thirty-four years.
B. Because it was made out of a rare material.
C. Because it was made on one night of 1943 by the Denver mint.
D, Because it was the only coin Denver mint made out of copper in 1943.
2.Before the Lincoln penny was sold, people thought one-cent coins __________.
A.were worth collecting for selling later |
B.were surely valuable if not made out of steel |
C.wouldn’t be sold for large amounts of money |
D.were only useful for some coin museums |
3.At least how many copper coins were made in 1943?
A.Five |
B.Twelve |
C.Seventeen |
D.Eighteen |
4.What can we learn about the collector who sold the penny?
A.He already had two copper pennies from 1943. |
B.He wanted to complete the set of copper pennies. |
C.He didn’t want to sell his penny in the beginning. |
D.He was a well-known coin dealer in Tampa, Horida. |