Green invaders are taking over America. Not invaders from space, but plants! You might not think of plants as dangerous, but in this case they are threatening nature's delicate food chain. The invaders are plants brought here from other countries to make gardens and yards look pretty. Ever since people started to arrive on America's shores, they have carried along trees, flowers, and vegetables from other places. Now there are so many of those plants, they are crowding out the native plants that have lived here since before human settlers arrived. And that's a problem, says Dr. Doug Tallamy. He's insect expert at the University of Delaware. He explains that almost all the plant-eating insects in the United States are specialized, which means they eat only certain plants. Monarch butterfly caterpillars ,for example, dine on milkweed. If people cut down milkweed and replace it with another plant, the butterflies will not have the food source that they need to survive. But the trouble doesn't stop there. When insects can't get the right plants to eat and they die off, then the birds don't have enough bugs for their meals. Tallamy points out that almost all migrating birds depend on insets to feed their young. "We cannot let the plants and animals around us disappear." says Tallamy, "The way to preserve them is to give them food to eat. But when we plant non-native plants, we are _ the food chain, because then we don't have the insects the birds need to live." Fewer of the right plants mean fewer bugs, and fewer bugs mean fewer birds. And that's bad for the Earth, because we need a variety of living things to keep the planet healthy and beautiful. The good news is, garden centers sell native plants. "Just Google 'native plants' and your location, and you can find out which plants really belong where you live," says Tallamy How did green invades arrive at America? A) They fell down from space. B) They floated to the America's shores. C) They were brought in from foreign countries D) They has lived here since human settlers arrived
C
(Question)
Is war unavoidable? Can war be prevented? History tells that there were wars, great or small, in every century, in every decade. Throughout the ages, from the Stone age to the Atomic Age, men have been fighting, first with swords and shields , then with guns and cannons, and now, hydrogen bombs and missiles are used for military purpose. But, in spite of all these, it is still my belief that war can be prevented and peace can be won, but it requires the effort of every one of us. I am sure that we would not like to experience another world war. If it ever happens, two-thirds of the world and much of the civilization which men have gained through time, patience and effort will be destroyed. Will then the remaining one-third of the world be able to survive on its own? Our task now is not to blame the past, but to plan for the future. If there is peace in the world, men can use their rockets to explore the mystery of space, their submarines to explore the depth of the sea, their missiles to deliver mails and their fine equipment to penetrate the jungles of Africa, instead of using them military. Governments can use their money to build more schools, so that more children can be educated to be useful citizens. Scientists can use atomic energy to propel steamships and planes. They can also design new machines to increase the production of goods and thus improve the way of living of the people. How can a peaceful world be achieved? It requires, in my opinion, the understanding and friendship between all people from all nations. Let no one suffer discrimination by reason of color, race, religion, or national origin. Let the rich support the poor and the strong help the weak. We know that neither peace nor such a dream world can come true in a day or a month. It may even take decades or centuries. But let us plan and begin now. We can infer from the passage that _ . A) wars were not expensive in the past B) wars can promote the development of weapons C) things for military use can be transformed to peaceful use D) as long as there are wars, people's way of living cannot be improved
(Answer)
C
Question: The triathlon promises to be one of the most popular Olympic sports.Recently it has drawn huge crowds attracted by athletes swimming 1,500m,cycling 40km,then running 10km without stopping.But what makes an attractive 17yearold girl give up everything for the doubtful pleasure it offers? Melanie Sears has not yet learnt those oftenrepeated phrases about personal satisfaction,mental challenge and higher targets that most athletes use when asked similar questions."You swim for 1,500m,then run out of the water and jump on your bike,still wet.Of course,then you freeze.When the 40km cycle ride is over,you have to run 10km,which is a long way when you're feeling exhausted.But it's great fun,and all worth it in the end," she says. Melanie entered her first triathlon at 14 and she won the junior section.Full of confidence,she entered the National Championships,and although she had the second fastest swim and the fastest run,she came nowhere."I was following this man and suddenly we came to the sea.We realised then that we had gone wrong.I ended up cycling 20 kilometres too far.I cried all the way through the running." But she did not give up and was determined that she never will."Sometimes I wish I could stop,because then the pain would be over,but I am afraid that if I let myself stop just once,I would be tempted to do it again."Such doggedness draws admiration from Steve Trew,the sport's director of coaching."I've just been testing her fitness," he says, "and she worked so hard on the running machine that it finally threw her off and into a wall.She had given it everything,and she just kept on." Melanie was top junior in this year's European Triathlon Championships,finishing 13th."I was almost as good as the top three in swimming and running,but much slower in cycling.That's why I'm working very hard at it." She is trying to talk her longsuffering parents,who will carry the PS1,300 cost of her trip to New Zealand for this year's world championships,into buying a PS2,000 bike,so she can try 25km and 100km races... What does Melanie say about her relationships with her teammates? A) She would like to see them more often. B) She only discusses the triathlon with them. C) She thinks they find her way of life strange. D) She dislikes discussing boys or clothes with them.
Answer:
B