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。
Winter begins in the north on December 22nd.People and animals have been doing what they always do to prepare for the colder months, squirrels, for example, have been busy gathering nuts from trees. 1.
They examined differences between red squirrels and gray squirrels in the American state of Indiana. The scientists wanted to know how these differences could affect the growth of black walnut(黑胡桃）trees. 2. The black walnut tree is also a central part of some hardwood forests.
Rob Swihart of Purdue University did the study with Jake Goheen, a former Purdue student nowat the University of New Mexico. The two researchers estimate that several times as many walnuts grow when gathered by gray squirrels as compared to red squirrels.Gray squirrels and red squirrels do not store nuts and seeds in the same way. Gray squirrels bury nuts one at a time in a number of places. 3. So some nuts remain in the ground. Conditions are right for them to develop and grow the following spring. Red squirrels, however, store large groups of nuts above ground.
4. But Professor Swihart says their numbers began to decrease as more forests were cut for agriculture. Red squirrels began to spread through the state during the past century. The researchers say red squirrels are native to forests that stay green all year, unlike walnut trees. They say the cleaning of forest land for agriculture has helped red squirrels invade（涌入）Indiana. 5.
A. Gray squirrels are native to Indiana.
B. But they seldom remember where they buried every nut.
C. Red squirrels bury nuts in a different way.
D. The black walnut is the nut of choice for both kinds of squirrels.
E. Jake Goheen calls them a sign of an environmental problem more than a cause.
F. Scientists are worried that they will drive away the gray squirrels.
G. Well, scientists have been busy gathering information about what the squirrels do with the food they collect.
Mars( 火星) appears to be flowing with small streams of salty water, at least in the summer, scientists reported Monday. "It suggests that. it would be possible for there to be life today on Mars," NASA's science mission chief, John Grunsfeld, said at a news conference on September 28, 2015.
The streams are about 12 to 15 feet wide and 300 feet or more long, scientists said. "What we're dealing with is wet soil. thin layers of wet soil, not standing water," said Aifred McEwen of the University of Arizona at Tueson ! the principal scientist for the Mars Reconnaissance Orbiter's high-resolution imaging experiment.
Because liquid water is essential to life, the findings could have major implications for the possibility of Martian life. The researchers said further exploration is needed to determine whether microscopic life exists on the planet.
The presence of liquid water could also make life easier for astronauts visiting or living on Mars. Water could be used for drinking and for creating oxygen and rocket fuel. NASA's goal is to send humans there in the 2030s.
The evidence of flowing water consists largely of dark, narrow streaks(条痕) on the surface that tend to appear and grow during the warmest Martian months and fade the rest of the year.
Mars is extremely cold even in summer, and the streaks are in places where the temperature is as low as minus 10 degrees Fahrenheit. But salt can lower the freezing point of water and melt ice.
The source(源头) of the water is a mystery. Scientists noted it could be melting ice. It could be an underground aquifer, which is rock or sand that can hold water. It is possibly water vapor from the thin Martian atmosphere, Or it may be a combination.
Michael Meyer, lead scientist for NASA's Mars exploration program, said the only definitive way for now to determine whether there's life on Mars is to collect rocks and soil for analysis on Earth - something a U. S. lander set for lift-off in 2020 will do.
1.What would be the best title for the text?
A Streams of Water Spotted on Mars
B. Astronauts will Land on Mars
C. NASA's Mars Exploration Program
D. A Breakthrough in the Exploration of Mars
2.According to John Grunsfeld, there seems to be on Mars.
A. salty water
B. standing water
C. rocket fuel
D. human beings
3.Scientists are uncertain about the of the water on Mars.
A. state
B. source
C. temperature
D. taste
4.What matters to the existence of liquid water on Mars?
A. The distance from the sun.
B. The favorable climate.
C. The gravity of the earth
D．The salt in it．
We all know what a brain is. A doctor will tell you that the brain is the organ of the body in the head. It controls our body's functions, movements, emotions and thoughts. But a brain can mean so much more.
A brain can also simply be a smart person, If a person is called brainy, she is smart and intelligent. If a family has many children but one of them is super smart, you could say, "She's the brains in the family. " And if you are the brains behind something you are responsible for developing or organizing something. For example, Bill Gates is the brains behind Microsoft.
Brain trust is a group of experts who give advice. Word experts say the phrase"brain trust" became popular when Franklin D. Roosevelt first ran for president in 1932, Several professors gave him advice on social and political issues facing the U. S.These professors were called his "brain trust. "
These ways we use the word "brain" all make sense. But other ways we use the word are not so easy to understand. For example, to understand the next brain expression, you first need to know the word“drain." As a verb to drain means to remove something by letting it flow away. So a brain drain may sound like a disease where the brain flows out the ears. But, brain drain is when a country's most educated people leave their countries to live in another. The brains are,sort of,draining out of the country.
However,if people are responsible for a great idea,you could say they brainstormed it. Here,brainstorm is not an act of weather. It is a process of thinking creatively about a complex topic. For example, business leaders may use brainstorming to create new products, and government leaders may brainstorm to solve problems.
If people are brainwashed, it does not mean their brains are nice and clean. To brainwash means to make someone accept new beliefs by using repeated pressure in a forceful or tricky way. Keep in mind that brainwash is never used in a positive way.
1.According to the text, if you're the CEO of Bai Du you can be called________.
A. the brains behind Bai Du
B. Bai Du's brain trust
C. the brain drain of Bai Du
D. the organ of Bai Du
2.Why did Roosevelt successfully win the election?
A. Because he was smart at giving advice.
B. Because word experts were popular.
C. Because he got his brain trust.
D. Because he was the brains behind America.
3.Which of the following expression is always used in a negative way?
A. Brain trust B. Brain drain
C. Brainstorm D. Brainwash
Giving Back
Fair Way
The Westborough High School golf team had taken the official photos with the state prize. The other teams, disappointed, were on the bus heading home. And the Westborough instructor Greg Rota noticed something wrong on one of the score cards. A 9 had been recorded as a 7. They were not the state prize winner; Wobum High had won. "No one would have known, said Wobum's instructor, Bob Doran. For Rota, it wasn’t a difficult decision: “The prize wasn’t ours to take.”
Coin Stars
"College students are lazy. but they also want to help," says University of Pennsylvania graduate. Dan Hork. So she made it easy, placing cups in rooms where students could leave their spare coins, and handing out cups to first-year students to keep in their rooms. Her "Change for Change" effort has collected$40,000 for charities, which were decided upon by students .
Never Forgotten
A school in Massachusetts received a $ 9. 5 million check from Jacques LeBermuth. But it took officials several days of digging to discover his connection to the school. Records showed the LeBermuth came from Belgium and studied in the school in the1920s. When his family fell on hard times, he was offered free room and board.LeBermuth became a trader, owned shares of AT&T and lived off the earnings until he died , at age 89.
1.What did Greg Rota probably do in the end?
A. Returned the prize to the organizer,
B. Apologized to Wobum High School.
C. Took photos of the state prize.
D. Had a meeting with Doran
2.Greg Rota's decision shows that he was .
A. polite B. honest
C. careful D. friendly
3.The underlined word "Change" in the second paragraph means__________.
A. Idea B. Decision C. Cups D. Coins
4.Jacques LeBermuth gave the money to the school because _________.
A. the school asked for it
B. he had no need for that much money
C. the school had helped him in the past
D. he wanted to be remembered by the students
Knowing how much her own children loved presents at Christmas, Ann Sutton always tried to seek help for one or two poor families. With a social worker mother, the Sutton children had inherited（继承）her commitment to service, and knew never to take their good fortune at Christmas for granted. This year, Kinzie, her seven-year-old daughter was thrilled that Santa Claus would make a special visit to a 22-year-old mother named Ashley who worked in a factory raising her 12-month-old son by herself.
The phone rang on Sunday. A representative from a local organization was calling to say that the aid Ann had requested for Ashley had fallen through. No Santa Claus, no presents, nothing.
Ann saw the cheer fade away from her children's faces at the news. Without a word, Kinzie ran into her bedroom. She returned, her face set with determination. Opening up her piggy bank, she put all the coins onto the table: $3.30. Everything she had.
“Mom," she told Ann, “I know it's not much. But maybe this will buy a present for the baby.”
At a breakfast meeting the next day, Ann told her coworkers about her daughter story. To her surprise, staff members began to open their purses. and empty their pockets to help Kinzie .
On Christmas Eve, Ann drove through the pouring rain to the small trailer where the Ashley’s lived. Then she began to unload the gifts from the car, handing them to Ashley one by one.
Ashley was very moved. Reflecting on a little girl's generosity, Ashley says she'll one day be able to do something similar for someone else in need. "Kinzie could have used that money for herself, but she gave it away," Ashley says. "She's the type of kid I'd like my son to grow up to be."
1.According to the text, Ann Sutton .
A. only cares about poor children
B. has possessed a good fortune
C. is warm-hearted and ready to help others
D. is a single mother with a 12-month-old boy
2.When hearing the aid had fallen through, Kinzie .
A. was not sad but cheerfu1
B. put all her coins away immediately
C. told her mother to ask the coworkers for help
D. decided to buy a present for the baby with all her allowance
3.From the text we can learn that _______. .
A. Ann would act as Santa Claus to hand out the Christmas presents
B. the Sutton children always got lots of presents at Christmas
C. Kinzie's generosity influenced others and they did something similar
D. Ashley was moved and promised to return the money
4.What does the text mainly talk about?
A. How a warm-hearted mother shows her love to a poor family.
B. How a mother and her young daughter helped a poor family.
C. Many people make contributions to those in need.
D. What happened to a poor family on Christmas Eve.
假定你是李华，你的美国朋友James来信说，他暑假后将到北京大学留学。请你根据以下内容给他写一封回信，告知有关情况。
1．简单介绍北京大学；
2．生活便利、居民友善；
3．留学期间，愿提供任何帮助。
注意：
1. 词数100左右；
2.可以适当增加细节，以使行文连贯；
3.通知的题目和结尾已给出，不计入总词数;
Dear James，
I am glad to know that you will come to China for further study．Now let me tell you what you are concerned about．
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
I’m looking forward to our meeting in Beijing.
Yours sincerely,
Li Hua
