US researchers have found traces of an ancient lake on Mars recently, increasing

US researchers have found traces of an ancient lake on Mars recently, increasing

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US researchers have found traces of an ancient lake on Mars recently, increasing hopes of discovering evidence that billions of years ago the Red planet hosted life.
The lake, which dates back some 3.4 billion years, appears to have covered as much as 80 square miles and was up to 1,500 feet deep, said the team from the University of Colorado.
“This is the first clear evidence of shorelines on the surface of Mars,”said Boulder’ s research associate, Gaetano Di Achille, in a study published in the latest edition of Geophysical Research Letters.
“The identification of the shorelines and accompanying geological evidence allows us to calculate the size and volume of the lake, which appears to have formed about 3.4 billion years ago.”
Analysis of the images has shown the water carved out the canyon (溪谷) in which it was found, which then opened out into a valley depositing (使淤积) sediment (沉积) which formed a delta (三角洲).
“Finding shorelines is a great discovery to us,” said assistant professor Brian Hynek, adding it showed the lake existed at a time when Mars was thought to have been cold and dry.
Scientists believe the oldest surfaces on Mars formed during the wet and warm era known as the Noachan epoch, about 4.1 billion to 3.7 billion years ago.
The newly discovered lake is believed to date from the Hesperian era and postdates the end of the warm and wet period on Mars by 300 million years, according to the study.
Scientists believe deltas next to the lake may well hold secrets about past life on Mars as such places on Earth have become the natural deposits of organic carbon and other markers of life.
小题1:The size of the lake found on Mars is ______.
A.80 square miles B.1,500 square miles
C.3.4 billion square milesD.300 million square miles
小题2:When the lake existed, the weather on Mars was ____.
A.hot and wet B.wet and warm C.cold and dryD.cold and wet
小题3:Why do scientists think deltas near the lake may hold secrets about past life on Mars?
A.Because similar places on Earth have become natural deposits of markers of life.
B.Because someone has put secrets about past life on Mars there.
C.Because past life has been found in other deltas on Mars.
D.Because some people are said to have already seen life marks there.
小题4:Which of the following statements is NOT true according to the passage?
A.The Noachan epoch was a wet and warm era.
B.The lake might have existed 3.4 billion years.
C.The discovery can’ t fully prove that the Mars once hosted life.
D.The lake traces prove that there exists life on Mars now.

答案

小题1:A
小题1:C
小题1:A
小题1:D
解析

举一反三
I have been a student at Bentley College in Waltham for some time now, so I have a lot of experience and know how things work at Bentley. As a freshman(新生)at Bentley College you will be living in the Tree Dorms, Slade Hall or Miller Hall. I would highly suggest that you choose to live in the Tree Dorms because this is where most fresh-men are going to be living. There will be a lot of activities going on in the building and you will meet lots of people. Slade Hall is next to the parking lot(停车场)and not far from the Tree Dorms, so that would be your second choice. As Miller Hall is small and far away, it would be my last choice for freshmen housing. If Bentley offers you the chance to live with second or third year students you’d better refuse their offer and live with freshmen. Living with your classmates will make the transition (过渡) into college life a lot easier.
As a freshman your classes should be easy. After freshman year your classes will become a lot more difficult, so I advise that you get down to business early in the first year. There are two very easy things you can do to increase your knowledge as a freshman. The first is to just go to class and the second is to always do your homework. I also highly advise that you do it on your own and try to stay disciplined(遵守纪律的). It is too easy to put your homework away and then get really behind and not be able to learn everything before a mid-term or final exam.
小题1:The author advises freshmen to live in the Tree Dorms because ___________.
A.it is across the parking lot from Slade Hall
B.it is small and quite far away from the playground
C.there are many second and third year students there
D.there are many freshmen and more activities
小题2:Where is Slade Hall?
A.Near Miller Hall.
B.Far from Tree Dorms.
C.Beside the car park.
D.Near the classrooms.
小题3:According to the author, how can freshmen improve knowledge?
A.Remember to do homework by discussing it with others.
B.Finish homework and go to class every day.
C.Try to spend more time in the library.
D.Be able to learn something before a mid-term or final exam.
小题4:The author writes the passage to ___________.
A.tell new students how to get used to college life
B.tell new students about their teachers and dormitory
C.show the differences between college and high school
D.tell readers about some funny things at Bentley College

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Having put down your pens at the end of the college entrance exam, you have ended 12 years of hard study. Forget your studies for a while. It’s time to enjoy yourselves!
There are many ways to celebrate this special month of graduation. You can have photos taken with your classmates and teachers, or dine out together and exchange gifts.
High school students in Western countries such as the United States and Canada usually have a prom to mark their graduation. It’s to mark the time kids turn into young men and women. After the prom, teenagers either go to college or find a job. It means they are no longer as dependent on their parents as they were before.
At the prom, boys usually dress in dinner jackets and bow ties, though many different types of formal clothes are worn. Traditionally, girls give boys matching boutonnieres ( 佩带在扣眼上的花). Girls traditionally wear formal dresses, or dress to shock or be noticed, in shiny or brightly colored materials.
Common prom activities include dining, dancing, the crowning (加冠) of a prom king and queen, and just talking to friends.  In some cases, high school students collect funds for their class prom through the four years of their high school.
High schools in or near large cities may rent ballrooms at expensive hotels or, to be unusual, in a pleasure cruise boat.
But often costs are cut by simply using the school gym. Students make a lot of effort to decorate the gym to make the event special. The music played at the prom will be the most popular kinds, like rock and hip-hop.
The students elect the Prom Queen. She is partnered with a Prom King who is elected similarly. These are great honors that the pair take very seriously. The two dance with each other to celebrate their election.
小题1:The word "prom" is probably closest in meaning with________.
A.a party to celebrate graduationB.a dancing competition
C.a fashion showD.an election ceremony
小题2:Which of the following is an economical way to hold the prom?
A.Renting a ballroom.B.Taking a cruise boat.
C.Holding it in the school gym.D.Wearing informal dresses.
小题3: What clearly indicates that prom is very important to students?
A.Music is played at the prom.
B.They take pictures at the prom.
C.The King and Queen dance with each other.
D.They wear formal clothes or special clothes.
小题4:For what do the students just talk to friends at a prom?
A.They don’t want to get help from their parents.
B.They will part with their friends in a short time.
C.They don’t like to be accompanied by their parents.
D.They want to be elected by their friends as the Prom King or Queen.
小题5:How is the prom significant to the students?
A.They can be relieved from the study pressure.
B.They are going to say goodbye to their friends.
C.They have chances to be elected as the Prom King or Queen.
D.The prom marks the graduation and after it they will be independent.

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When Emily Beardmore first heard that a trip was being planned by the biology class at Windsor High School, she thought about how much fun it would be.
“I thought it would be a really good experience to go with other friends and teachers to another country in an environment other than a vacation environment,” the 17-year-old girl said.
A few months later, Emily got her chance when she and 14 of her classmates, along with biology teacher Tamara Pennington went to Costa Rica for eight days in late May.
“It was not just a tour,” said Pennington, who organized the trip. “You can go any place in the world on just a tour. This one was really working with the sea turtles (海龟) and practicing conservation(保护). It just seemed like the perfect science field trip for kids who think they want to get into science to see what it"s really like to be out in the field and enjoy themselves.”
Emily said her time on the turtle program, which was the focus of the trip, was “crazy.”“We were walking on the beach at night and you can’t see anything—just see a big black dot.” She said with a laugh. “I was not expecting the turtles to be that big.” The turtles are leatherback turtles, which are becoming extinct (灭绝) because their eggs are used as food.
“When they would move their legs while laying their eggs they were really hard to control because they were a lot more powerful than you would imagine,” Emily said.
Once the eggs were collected, the students took them back to a hatchery(孵化场) and dug holes to copy the hole the mother turtle had made and then buried the eggs for the 60 days needed to hatch.
“The experience was so cool,” Emily said. “You go to another country to see what their culture is like and learn what their everyday lives are like. It made me really want to help out my mom a lot more than I do, and value what I have.”
小题1:What did Pennington consider the trip to be?
A.It was a common tour to a foreign country.
B.It was a journey to practice what students learned.
C.It was to attract students’ interest in science.
D.It was a trip to do practical science activities.
小题2:From what Emily said on her turtle program, we know that     .
A.she was afraid of walking on the beach at night
B.she didn’t dare to catch the powerful turtles
C.she had thought turtles were small animals
D.she got crazy at the sight of turtles at night
小题3:What did Emily learn from her experience?
A.She learned to be grateful to her teachers.
B.She understood the importance of what she had.
C.She realized the beauty of foreign culture.
D.She knew the importance of everyday life
小题4:What would be the best title for the passage?
A.Teens Help Fight Turtle Extinction.
B.Teens Take a tour to Costa Rica.
C.Teens Have a Research on Turtles.
D.Teens Learn to be Independent.

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Use the iPhone while charging it. Even charge the RichardSolo 1800 and iPhone together at the same time. Take only one charger when traveling and wake up in the morning with the RichardSolo and the iPhone charged.
RichardSolo 1800 is largest in its class and holds its charge for months. Works with almost all iPhone cases.
Your satisfaction is guaranteed, with our 30-day return privilege. If you’re not satisfied for any reason, we’ll email you a pre-paid return label.
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小题1: How long does it take the battery to charge up an iPhone?
A.15 minutes.B.30 minutes.C.1.5 hours.D.3 hours.
小题2:What is special about the battery?
A.It is built in an iPhone.B.It is the smallest of its kind.
C.It can also be used as a charger.D.It keeps power for about 30 days.
小题3: If you are not satisfied with the product, you ______.
A.may get your pre-paid money back with any reason
B.can demand an apology and the money back within 30 days
C.have the privilege of one-month return without any reason
D.are probably unable to have the return privilege with a return label
小题4:Who mentions the transporting of the battery?
A. P.S.     B. B.L.     C. M.C.     D. T.K.
小题5:The customer comments on the battery are mainly about its _______.
A.qualityB.serviceC.functionD.shopping

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A weather map is an important tool for geographers.   A succession of three or four maps presents continuous picture of weather changes. Weather forecasters are able to determine the speed of air masses and fronts (气锋) to determine whether an individual pressure aroa is deepening or becoming shallow and whether a front is increasing or decreasing in intensity (强烈).They are also able to determine whether an air mass is retaining its original characteristics or taking on those of the surface over which it is moving. Thus, a most significant function of the map is to reveal a summary picture of conditions in the atmosphere at a given time.
All students of geography should be able to interpret a weather map accurately.Weather maps contain an enormous amount of information about weather conditions existing at the time of observation over a large geographical area. They reveal in a few minutes what otherwise would take hours to describe. The United States  Weather Bureau issues information about approaching storms, floods, frosts and all climatic conditions in general. Twice a month it issues a 30-day"outlook" which is a rough guide to weather conditions likely to occur over broad areas of the United States. These 30-day outlooks are based upon an anaiysis of the upper air levels which often set the stage for development of air masses, fronts and storms.
Considerable effort is being exerted today to achieve more accurate weather
predictions, with identifying and tracking storms over regions which have but few meteorological (气象)stations. Extensive experiments are also in progress for weathef modification studies.
小题1: One characteristic of weather maps NOT mentioned by the author in this passage is_______.
A.floodsB.frontsC.temperature changesD.frosts
小题2: The thirty-day forecast is determined by examining________.
A.daily weather mapsB.upper air levels
C.satellite reportsD.changing fronts
小题3:The observation of weather conditions by satellites is helpful because it________
A.is modern
B.uses electronic instruments
C.makes weather prediction easier
D.shows things that would otherwise take hours to describe in a few minutes
小题4:A weather map is a summary because it_______
A.sums up a great deal of informationB.appears daily
C.shows changing frontsD.is a science book
小题5:You may possibly read this article in_________.
A.a magazineB.newspaperC.a novelD.a science book

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