A.AT LAST B.EVENTUALLY C.LASTLY D.IN THE ENDREAD THE FOLLOWING PASSAG...

Câu 30: A.at last B.eventually C.lastly D.in the endRead the following passage and mark the letter A, B, C, or D on your answer sheet to indicate thecorrect answer to each of the questions from 31 to 37.A rather surprising geographical feature of Antarctica is that a huge freshwater lake, one of theworld's largest and deepest, lies hidden there under four kilometers of ice. Now known as LakeVostok, this huge body of water is located under the ice block that comprises Antarctica. The lake isable to exist in its unfrozen state beneath this block of ice because its waters are warmed bygeothermal heat from the earth's core. The thick glacier above Lake Vostok actually insulates it fromthe frigid temperatures on the surface.The lake was first discovered in the 1970s while a research team was conducting an aerial surveyof the area. Radio waves from the survey equipment penetrated the ice and revealed a body of waterof indeterminate size. It was not until much more recently that data collected by satellite madescientists aware of the tremendous size of the lake; the satellite-borne radar detected an extremely flatregion 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 thescientific community because of the potential that the lake contains ancient microbes that havesurvived for thousands upon thousands of years, unaffected by factors such as nuclear fallout andelevated ultraviolet light that have affected organisms in more exposed areas. The downside of thediscovery, however, lies in the difficulty of conducting research on the lake in such a harsh climateand in the problems associated with obtaining uncontaminated samples from the lake without actuallyexposing the lake to contamination. Scientists are looking for possible ways to accomplish this.