Astronomers have captured  the first direct image of a planet being born. Adam Kraus, of the University of Hawaii's Institute for Astronomy, said the planet is being formed out of dust and gas circling a 2-million-yea-old star about 450 light years from Earth. The planet itself, based on scientific models of how planets form, is believed to have started taking shape about 50,000 to 100,000 years ago. Called LkCa 15b, it's the youngest planet ever observed. The previous record holder was about five times older. Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea(a volcano on the island of Hawaii, US) to find the planet. Kraus presented the discovery Wednesday at NASA's Goddard Space Flight Center in Maryland. Observing planets while they're forming can help scientists answer questions like weather planets form early in the life of a star or later, and whether they form relatively close to stars or father away. Planets can change orbits  after forming, so it's difficult to answer such questions by studying older planets. "These very basic questions of when and where are best answered when you can actually see the planet forming, as the process is happening right now," Kraus said. Scientists hadn't been able to see such young planets before because the stars they're circling around outshine  them. Kraus and Ireland used two techniques to overcome this problem.[:++] One method, which is also used by other astronomers, was to change the shape of the telescope mirrors to remove light distortion  created by the Earth's atmosphere. The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors. The combination of these techniques allowed the astronomers to obtain high-quality images that let them see the planet next to the bright star. The star LkCa 15--the planet is named after its star--was the team's second target. They immediately knew they were seeing something new,... The research on younger planets helps scientists   _  . A) study why planets change orbits after forming B) understand how planets move around their stars C) answer questions about the age of stars and planets D) know the relationship between planets and their stars
D


At one time no one could travel on an English road faster than four miles an hour. That was the law until 1896. A man had to walk in front of a car which could not go faster than the man. At night the man had to carry a red lamp. Once Charles Rolls brought a car from France to England, but he wanted to drive faster than four miles an hour. In order to have no trouble with the police, he had a talk with some of the police officers, who ordered their policemen to look the other way when the car came along the road. This was a good plan in the country, but not so easy to follow in the busy streets of London. One night Rolls and some friends started from London on their journey to Cambridge. One of the men walked in front with the red lamp, but he walked as fast as he could. The police became very interested in walls and shop-fronts when they heard the car and not one of them saw it. They reached a hill, but what a waste of time it was to drive down the hill at four miles an hour! Rolls was getting ready to jump into the car, but then he noticed a policeman who was not looking the other way. The slow car reached him. "Good evening," said the policeman, looking at the car. "Good evening," said Rolls, holding the lamp. "One of these horseless things," said the policeman, looking at it with interest. "Yes," said Rolls, and waited. "I've often wanted a ride in one, but of course policemen can't buy things like that." He turned and looked hopefully in Rolls's face. "Jump in," said Rolls. "Thanks," said the policeman, and did so. "Now," he said, sitting down, "You can let it go just as you like down this hill. There isn't another policeman on this road for a mile and a half." In what way did the policemen carry out the order from their officers? A) They greeted Rolls when the car came along. B) They walked in front of the car with a red lamp. C) They pretended to be attracted by something else. D) They stood on duty every 1.5 miles along the road.
C


Q: Life is filled with challenges. As we get older we come to realize that those challenges are the very things that shape us and make us who we are,it is the same with the challenges that come withfriendship.When we are faced with a challenge,we usually have two choices. We can try to beat it off, or we can decide that the thing presenting the challenge isn't worth the trouble and call it quits.Although there are certainly times when calling it quits is the right thing to do,in most cases all that is needed is commitment and communication. When we are _ to something, it means that no matter how painful or howuncomfortable something is,we will always choose to face it through instead of running away from it.Communication is making a space for discussion and talking about how you feel as opposed to just saying what the other person did wrong. If you can say to a friend,"I got my feelings hurt." rather than"You hurt my feelings."you are going to be able to solve the problem much faster. In dealing with many challenges that friendship will bring to you, try to see them for what they are:small hurdles you need to jump or get through on your way through life.Nothing is so big that it is impossible to get over, and hurt only serves to make us stronger.It is all part of growing up,it happens to everyone,and some day you will look back on all of this and say,"Hard as it was,it made me who I am today.And that is a good thing." It can be inferred from the text that   _  . A) friendship needs challenges B) challenges shape our character C) small hurdles aren't worth the trouble D) commitment promotes friendship
A: B


*Question*
Trees are useful to man in three important ways: They provide him with wood and other products; they provide him shade;. and they help to prevent droughts and floods. Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important.In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear. This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind the soil, thus preventing it from being washed away easily;but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert. Two thousand years ago,a rich and powerful country cut down its trees to build warships, with which to gain itself an empire .It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation . Which title best fits the passage? A) Trees and Man B) How Trees Prevent Droughts and Floods C) How an Empire Fell D) A Story about Trees.
**Answer**

A