Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.
A rather surprising geographical feature of Antarctica is that a huge freshwater lake, one of the world's largest and deepest, lies hidden there under four kilometers of ice. Now known as Lake Vostok, this huge body of water is located under the ice block that comprises Antarctica. The lake is able to exist in its unfrozen state beneath this block of ice because its waters are warmed by geothermal heat from the earth's core. The thick glacier above Lake Vostok actually insulates it from the frigid temperatures on the surface.
The lake was first discovered in the 1970s while a research team was conducting an aerial survey of the area. Radio waves from the survey equipment penetrated the ice and revealed a body of water of indeterminate size. It was not until much more recently that data collected by satellite made scientists aware of the tremendous size of the lake; the satellite-borne radar detected an extremely flat region where the ice remains level because it is floating on the water of the lake.
The discovery of such a huge freshwater lake trapped under Antarctica is of interest to the scientific community because of the potential that the lake contains ancient microbes that have survived for thousands upon thousands of years, unaffected by factors such as nuclear fallout and elevated ultraviolet light that have affected organisms in more exposed areas. The downside of the discovery, however, lies in the difficulty of conducting research on the lake in such a harsh climate and in the problems associated with obtaining uncontaminated samples from the lake without actually exposing the lake to contamination. Scientists are looking for possible ways to accomplish this.
The purpose of the passage is to __________.
A. explain how Lake Vostok was discovered
B. provide satellite data concerning Antarctica
C. discuss future plans for Lake Vostok
D. present an unexpected aspect of Antarctica's geography
Đáp án D.
Key words: purpose of the passage
A. explain how Lake Vostok was discovered: giải thích hồ Vostok được phát hiện như thế nào
B. provide satellite data concerning Antarctica: cung cấp dữ liệu vể tính liên quan đến Nam Cực
C. discuss future plans for Lake Vostok: bàn về kế hoạch tương lai cho ho Vostok
D. present an unexpected aspect of Antarctica’s geography: giới thiệu một khía cạnh bất ngờ của địa lý Nam Cực
Ta thấy bài viết được mở đầu bang “A rather surprising geographical feature of Antarctica”: “Một đặc điểm địa lý khá ngạc nhiên của Nam Cực ” và cả bài viết đều nói về đặc điểm này (hồ nước ngọt Vostok) nên đáp án chính xác là D.