51.What can't you do in the Moon Hunter Party l ob woH 02 A.Eat some food. B.Listen to music. C.Make friends. D.Sing songs. 52.Which is the correct way to carry the flashlight B D 53.When is better for you to arrive if you bring your own telescope A.Before 6:00 p.m. B.At 6:30 p.m. C.Before 9:30 p.m. D.At10:00p.m. 54.What does the success of the party depend on A.The food. B.The weather. C.The website. D.The clothes. 55.Who is the passage written for A.Parents. B.Kids. C.Teenagers. D.Teachers. 21 B Sea grasses are flowering plants that grow in waters near coasts.They grow together in thick fields,known as meadows.Sea grass meadows help clean the ocean's water.They also provide food for animals like fish.The climate change and human pollution are threatening sea grass meadows in many places around the world.But the huge sea grass meadow in Shark Bay,off the coast of Western Australia,seems to be growing very well.It's a kind of sea grass called Posidonia australis,and it has spread widely all through Shark Bay. Scientists from The University of Western Australia and Flinders University wanted to study the sea grass,so they took samples (from 10 different parts of this huge meadow.By comparing the DNA from their samples,the scientists hoped to get an idea of how many different sea grass plants there were in the meadow.What they learned shocked them-all of the grass samples had almost exactly the same DNA.It meant that they were all just one plant.One big sea grass plant spread out over 200 square kilometers.This makes it the largest known plant in the world,by far. So how has the Shark Bay sea grass grown so large Instead of spreading with flowers and seeds(), it spreads by cloning (itself.As its roots (spread out under the sea floor,new plants shoot up from those roots.The Shark Bay sea grass generally grows and spreads about 35 centimeters a year. From this,the scientists believe that the plant is about 4,500 years old. 56.What does the underlined word"threatening"in the first paragraph mean b m A.Giving help to. C.Planting more. B.Bringing danger to. Bnin avsb ood D.Improving 57.What did the scientists want to know about the meadow from the samples A.The area it covers. ado由atbn B.The reason why it has grown so large. C.The water pollution it faces. D.The number of the sea grass types of it. 58.Where do new plants for the sea grass grow A.From its roots. C.From its flowers. n boot wo woy B.From its seeds. D.From another plant. 第7页（共10页）
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