【单选题】
GreatBarrier Reef
The GreatBarrier Reef is made of coral, a colorful rock-like substance actually composed of many small marine animals, each one less than half a centimeter in size.Coral grows in colonies that can reach over a meter and a half in height, and several of these colonies grow in close proximity to each other, eventually joining up to form an underwater chain or reef. The GreatBarrier Reef refers to a series of almost three thousand coral reefs that stretch across the ocean floor in a twelve hundred mile chain, which makes it so long that it can actually be seen from space.Apart from its size, the GreatBarrier Reef is also renowned for its age. The living part of the reef itself is around 8,000 years old, but sits atop the remains of dead coral that is much older, in some places almost half a million years ol
D、A、system of living organisms so anc ient and so large would be fascinating to scientists by the simple fact of its existence alone, but the GreatBarrier Reef is also of great scientific interest because of the diversity of marine life that lives in its vicinity.
As stated above, the GreatBarrier Reef is made of coral, but just as there are many different varieties of dogs, cats, and finches, there are many varieties of coral, over 500 of which are found in the GreatBarrier Reef. The rocky formations of the reefs also provide shelter for a variety of smaller marine fish, and these in turn provide food for larger, more predatory fish.As a result, some scientists believe that the Reef is home to up to twenty-five percent of all marine fish species. However, this is only a rough estimate since so few of the Reef’s fish species have been documente
D、In addition, the Reef hosts a variety of sponges, anemones, sea turtles, sea snakes, sea birds, and whales. Marine biologists, therefore, value the Reef for what it can teach them about ocean ecology, while other scientists are eagerly investigating the practical applications of chemical compounds produced by the creatures of the Reef. Indeed, chemicals initially discovered in Reef organisms are already the basis for many potent new medicines, including some that help battleAIDS and various cancers.
Coral reefs in general, and the GreatBarrier Reef in particular, have been considered so environmentally important that the governments that control the waters where they exist have designated vast tracts of ocean as environmentally protected areas. Nevertheless, the reefs form one giant, interconnected ecosystem, and human activities in unprotected areas of the reefs can affect the entire system. One such human activity is fishing. ■
A、The rich biodiversity of the reefs attracts many predatory fish that in turn draw large numbers of fishing vessels. ■
B、Unfortunately, many modern fishing techniques employ nets that catch not only the target species, but all fish too big to slip through the holes in the net. ■
C、Besides fishing, the reefs face pressure from shipping and oil spills. ■
D、Shipping can become a problem when freighters make mistakes in navigation and run into the reef,
shattering segments of it that have taken decades or even centuries to grow. Oil spills-- always damaging to the environment--have an especially devastating effect when they occur near the reefs because so many endangered species are affecte
D、
The future of the GreatBarrier Reef is uncertain. In addition to the environmental hazards outlined above, the Reef is under threat of global warming.Although coral consists of tiny, carnivorous animals, those animals do not get most of their nutrients from the organisms they catch. Instead, they enjoy a symbiotic relationship with a form of algae called zooxanthellae. These algae live off the nitrogen emitted by the coral. Like many other types of algae, zooxanthellae undergo photosynthesis, using energy from sunlight to create sugars that they can use for fue
网考网参考答案：B
网考网解析：
[解析] 指代关系题 指示代名词所指代的名词一般出现在指示代名词所在的句子或者前一个句子中。Although coral consists of tiny, carnivorous animals, those animals do not get most of their nutrients from the organisms they catch这句中they指代的是从捕获的有机体中不能获得大部分养料的复数名词。在该句中，有此含义的单词是animals。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>
The GreatBarrier Reef is made of coral, a colorful rock-like substance actually composed of many small marine animals, each one less than half a centimeter in size.Coral grows in colonies that can reach over a meter and a half in height, and several of these colonies grow in close proximity to each other, eventually joining up to form an underwater chain or reef. The GreatBarrier Reef refers to a series of almost three thousand coral reefs that stretch across the ocean floor in a twelve hundred mile chain, which makes it so long that it can actually be seen from space.Apart from its size, the GreatBarrier Reef is also renowned for its age. The living part of the reef itself is around 8,000 years old, but sits atop the remains of dead coral that is much older, in some places almost half a million years ol
D、A、system of living organisms so anc ient and so large would be fascinating to scientists by the simple fact of its existence alone, but the GreatBarrier Reef is also of great scientific interest because of the diversity of marine life that lives in its vicinity.
As stated above, the GreatBarrier Reef is made of coral, but just as there are many different varieties of dogs, cats, and finches, there are many varieties of coral, over 500 of which are found in the GreatBarrier Reef. The rocky formations of the reefs also provide shelter for a variety of smaller marine fish, and these in turn provide food for larger, more predatory fish.As a result, some scientists believe that the Reef is home to up to twenty-five percent of all marine fish species. However, this is only a rough estimate since so few of the Reef’s fish species have been documente
D、In addition, the Reef hosts a variety of sponges, anemones, sea turtles, sea snakes, sea birds, and whales. Marine biologists, therefore, value the Reef for what it can teach them about ocean ecology, while other scientists are eagerly investigating the practical applications of chemical compounds produced by the creatures of the Reef. Indeed, chemicals initially discovered in Reef organisms are already the basis for many potent new medicines, including some that help battleAIDS and various cancers.
Coral reefs in general, and the GreatBarrier Reef in particular, have been considered so environmentally important that the governments that control the waters where they exist have designated vast tracts of ocean as environmentally protected areas. Nevertheless, the reefs form one giant, interconnected ecosystem, and human activities in unprotected areas of the reefs can affect the entire system. One such human activity is fishing. ■
A、The rich biodiversity of the reefs attracts many predatory fish that in turn draw large numbers of fishing vessels. ■
B、Unfortunately, many modern fishing techniques employ nets that catch not only the target species, but all fish too big to slip through the holes in the net. ■
C、Besides fishing, the reefs face pressure from shipping and oil spills. ■
D、Shipping can become a problem when freighters make mistakes in navigation and run into the reef,
shattering segments of it that have taken decades or even centuries to grow. Oil spills-- always damaging to the environment--have an especially devastating effect when they occur near the reefs because so many endangered species are affecte
D、
The future of the GreatBarrier Reef is uncertain. In addition to the environmental hazards outlined above, the Reef is under threat of global warming.Although coral consists of tiny, carnivorous animals, those animals do not get most of their nutrients from the organisms they catch. Instead, they enjoy a symbiotic relationship with a form of algae called zooxanthellae. These algae live off the nitrogen emitted by the coral. Like many other types of algae, zooxanthellae undergo photosynthesis, using energy from sunlight to create sugars that they can use for fue
网考网参考答案：B
网考网解析：
[解析] 指代关系题 指示代名词所指代的名词一般出现在指示代名词所在的句子或者前一个句子中。Although coral consists of tiny, carnivorous animals, those animals do not get most of their nutrients from the organisms they catch这句中they指代的是从捕获的有机体中不能获得大部分养料的复数名词。在该句中，有此含义的单词是animals。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>
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