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 in which it was found, which then opened out into a valley depositing sediment which formed a delta . "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. 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.
A
(Question)
Do you love the holidays,but hate the pounds that follow? You are not alone. Holidays are times for feasting and celebrating. Many people are worried about their weight.With proper planning,though,it is possible to keep normal weight during the holidays.Whether it is celebrating at the office party or sitting down for the traditional family dinner,regard eating as a time for tasting a variety of the foods.The idea is to enjoy the holidays but not to eat too much. You don't have to turn away from the foods that you enjoy. Here are some tips for preventing weight gain and maintaining physical fitness: Don't skip meals.Before you leave home,have a small,low-fat meal or snack.This may help to avoid getting too excited before delicious foods. Control portions.Use a small plate (about 10 inches) and put aside the large ones that may encourage you to "load up." You should be most comfortable eating an amount of food about the size of your fist. Once you have your "tasting" serving,move away from the buffet . Doing so will make it less tempting to be eating constantly as your appetite is inspired by the sight of food. Begin with soup and fruit or vegetables. Fill up beforehand on water-based soup and raw fruit or vegetables. Or drink a large glass of water before you eat to help you feel full. Stick to physical activity. Don't let exercise take a break during the holidays. A 20-minute walk after a meal can help burn off excess calories. Avoid high-fat foods. Dishes that look oily or creamy may have a large amount of fat. Choose lean meats. Fill your plate with salad and green vegetables. Use lemon juice instead of dessert or butter. Which of the following CANNOT help lose weight according to the passage? A) Lean meats. B) Dessert or butter. C) Raw fruit or vegetables. D) Physical exercise.
(Answer)
B
Ques: Samuel Osmond is a 19-year-old law student from Cornwall, England. He never studied the piano. However, he can play very difficult musical pieces by musicians such as Chopin and Beethoven just a few minutes after he hears them. He learns a piece of music by listening to it in parts. Then he thinks about the notes in his head. Two years ago, he played his first piece Moonlight Sonata by Beethoven. He surprised everyone around him. Amazed that he remembered this long and difficult piece of music and played it perfectly, his teachers say Samuel is unbelievable .They say his ability is very rare, but Samuel doesn't even realize that what he can do is special. Samuel wanted to become a lawyer as it was the wish of his parents, but music teachers told him he should study music instead. Now, he studies law and music. Samuel can't understand why everyone is so surprised. "I grew up with music. My mother played the piano and my father played the guitar. About two years ago, I suddenly decided to start playing the piano, without being able to read music and without having any lessons. It comes easily to me ---I hear the notes and can bear them in mind---each and every note," says Samuel. Recently, Samuel performed a piece during a special event at his college. The piece had more than a thousand notes. The audience was impressed by his amazing performance. He is now learning a piece that is so difficult that many professional pianists can't play it. Samuel says confidently," It's all about super memory---I guess I have that gift." However, Samuel's ability to remember things doesn't stop with music. His family says that even when he was a young boy, Samuel heard someone read a story, and then he could retell the story word for word. Samuel is still only a teenager. He doesn't know what he wants to do in the future. For now, he is just happy to play beautiful music and continue his studies. What is special about Samuel Osmond? A) He has a gift for writing music. B) He can write down the note he hears. C) He is a top student at the law school. D) He can play the musical piece he hears.
Ans: D
New research shows that the healthy brain may hold memories which we don't even remember. In The Journal of Neuroscience, experts report that the brain might hold more memories than people realize, but that restoring those memories can be tricky. Memory Check First, participants saw a list of 120 real words mixed with 80 nonsense words. Next, they saw another word list and tried to remember which words had been on the first list. Meanwhile, their brains were scanned with functional magnetic resonance imaging. While participants reviewed the second word list, their brain scans showed more activity in a certain brain area -- the posterior median temporal lobe -- when they saw words that had been on the first word list. But participants didn't always remember that they'd seen those words before. Sometimes, they _ and said they hadn't seen those words before. In other words, the posterior median temporal lobe was more sensitive to memory than participants' consciousness, the researchers note. "Album"of Memories Another part of the median temporal lobe also attracted the scientists' attention. The anterior median temporal lobe showed more activity when participants thought they were seeing a new word, the study shows. So, why did participants sometimes mess up their memory recall? It might be that two parts of their brain -- the posterior and anterior median temporal lobes -- might be dueling for the upper hand in deciding what actually happened in the past, the study notes. In other words, memories might have a photo album in the brain, but sometimes we forget what's on all of the photo album's pages. What did the experts discover when the participants saw the words on the first word list appear on the second word list? A) The instrument worked faster. B) The participants were more conscious. C) The posterior median temporal lobe was more active. D) The anterior median temporal lobe was more active.
C