1 . Coral reefs are some of the most diverse and valuable ecosystems on Earth. Coral reefs support more species per unit area than any other marine (海洋的) environment, including about 4,000 species of fish, 800 species of hard corals and hundreds of other species. Scientists estimate that there may be millions of undiscovered species living in and around reefs. This biodiversity is considered the key to finding new medicines for the 21st century. Many drugs are now being developed from coral reef animals and plants as possible cures for cancer, viruses, and other diseases.
Healthy coral reefs support fisheries as well as jobs and businesses through tourism and recreation. About half of all managed fisheries depend on coral reefs and related habitats for a part of their life cycles. The National Marine Fisheries Service estimates the commercial value of U. S. fisheries from coral reefs is over $ 100 million, Local economies receive billions of dollars from visitors to reefs through diving tours, recreational fishing trips, hotels, restaurants, and other businesses based near reef ecosystems.
Coral reef structures also buffer (缓冲) shorelines against 97 percent of the energy from waves, storms, and floods, helping to prevent loss of life, and property damage. When reefs are damaged or destroyed, the absence of this natural barrier can increase the damage to coastal communities from normal wave action and violent storms. Several million people live in U. S. coastal areas near coral reefs. Some coastal development is required to provide necessary infrastructure (基础设施) for coastal residents and the growing coastal tourism industry.
Despite their great economic and recreational value, coral reefs are severely threatened by pollution, disease, and habitat destruction. Once coral reefs are damaged, they are less able to support the many creatures that live on them and the communities near them. When a coral reef supports fewer fish, plants, and animals, it also loses value as a tourist destination.
1. Why is biodiversity important to medicines?| A．It can reduce the prices of new medicines. | B．It can help make new medicines. |
| C．It can be used for medicines. | D．It can be used to cure diseases. |
| A．They protect people against sharks. | B．They completely avoid serious flooding. |
| C．They prevent people from being drowned. | D．They weaken most of the energy from waves. |
| A．Most fish will die out. | B．Coastal cities will attract fewer tourists. |
| C．There will be no large fish. | D．The sea will be polluted. |
| A．The Importance of Diverse Ecosystems | B．The Environments of Coral Reefs |
| C．The Importance of Coral Reefs | D．The Value of Biodiversity |
2 . Rainforests are home to a rich variety of medicinal plants, food, birds and animals. Can you believe that a single bush（灌木丛）in the Amazon may have more species of ants than the whole of Britain! About 480 varieties of trees may be found in just one hectare of rainforest.
Rainforests are the lungs of the planet-storing vast quantities of carbon dioxide and producing a significant amount of the world's oxygen. Rainforests have their own perfect system for ensuring their own survival; the tall trees make a canopy（树冠层）of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, intense dry heat from the sun and strong winds.
Amazingly, the trees grow in such a way that their leaves and branches, although close together, never actually touch those of another tree. Scientists think this is the plants' way to prevent the spread of any tree diseases and make life more difficult for leaf-eating insects like caterpillars. To survive in the forest, animals must climb, jump or fly across the gaps. The ground floor of the forest is not all tangled leaves and bushes, like in films, but is actually fairly clear. It is where dead leaves turn into food for the trees and other forest life.
They are not called rainforests for nothing! Rainforests can generate 75%of their own rain. At least 80 inches of rain a year is normal-and in some areas there may be as much as 430 inches of rain annually. This is real rain-your umbrella may protect you in a shower, but it won't keep you dry if there is a full rainstorm. In just two hours, streams can rise ten to twenty feet. The humidity（湿气）of large rainforests contributes to the formation of rainclouds that may travel to other countries in need of rain.
1. What can we learn about rainforests from the first paragraph?| A．They produce oxygen. | B．They cover a vast area. |
| C．They are well managed. | D．They are rich in wildlife. |
| A．Heavy rains | B．Big trees. |
| C．Small plants. | D．Forest animals. |
| A．For more sunlight. | B．For more growing space. |
| C．For self-protection. | D．For the detection of insects. |
| A．Life-Giving Rainforests | B．The Law of the Jungle |
| C．Animals in the Amazon | D．Weather in Rainforests |
3 . Theaters of the Past
The Greek Theater
Theaters developed in many parts of Greece. Ancient Greek theaters were built in natural open air sites on conveniently shaped hills. This allowed a great mass of people to enjoy a show at a time. Due to this, actors placed emphasis on exaggerated (夸张的) action and speech. And, colorful symbolic masks and costumes were used.
The Medieval Theater
The Medieval theater started in churches. That’s why medieval plays were about Bible stories. At first, it became a custom for priests (牧师) to act out brief scenes during Christmas and Easter. These acts attracted large crowds. Finally the church refused to allow priests to participate in any such events again, so ordinary people began these performances outside. Performances were set in the town square, with several stage settings around it.
The Elizabethan Theater
The England’s theater developed rapidly in the years following the defeat of the Spanish Navy. The dominant feature of Elizabethan theater was the stage, It has three parts: The fore stage for outside scenes ;the inner stage for scenes inside a building; an upper stage or balcony for various purposes. The reason for this design is that there were no scene changes, or breaks during the play. Very little scenery was used, so the actors had to create a scene through their voices and dialogues. This led to a more poetic script , and poets became the main source of script writing.
The Restoration Theater
Some of the plays told sad stories, but the majority of the plays were really funny. Many specialized machines were used to create the scene. The stage was a very clever idea , in that on the sides of the stage large back shutters (百叶窗) were painted with the scene.
1. Why were ancient Greek theaters built on hills?| A．To hold a large audience. |
| B．To build a big and strong stage. |
| C．To have a better sound effect. |
| D．To emphasize exaggerated performances. |
| A．The Greek Theater. |
| B．The Medieval Theater, |
| C．The Elizabethan Theater, |
| D．The Restoration Theater. |
| A．Colorful masks were used. |
| B．The stage was smartly designed. |
| C．Most of its plays were sorrowful. |
| D．Ordinary people were the performers. |
Long ago the Panamint Indians called this place "Tomesha"-- the land of fire. Death Valley's present name dates back to 1849, when a group of miners coming across from Nevada became lost in its unpleasantness and hugeness and their adventure turned out to be a sad story. Today Death Valley has been declared a National Monument and is crossed by several well-marked roads where good services can be found easily. Luckily the change created by human settlement has hardly ruined the special beauty of this place.
Here nature created a lot of surprising, almost like the sights on the moon, ever-changing as the frequent wind moves the sand about, showing the most unusual colors. One of the most astonishing and colorful parts of Death Valley is the Devil's Golf Course, where it seems hard for one to tell reality from dreams. Sand sculptures stand on a frightening ground, as evening shadows move and lengthen.
1. The name of the valley comes from__________ .
| A．an Indian name | B．the death of the miners |
| C．the local people | D．a National Movement |
| A．no one had ever known the desert before the miners |
| B．it's still not easy to travel across the desert |
| C．people can find gas-stations, cafes and hotels in the desert |
| D．people have changed the natural sight of the desert |
| A．the terrible sights | B．the moon-like sights |
| C．dream-like sights | D．the ever-changing sights |
| A．appreciates | B．is fearful of | C．dislikes | D．is tired of |
