问题详情：
It was early in the afternoon of May 10, 1996. I hadn’t slept in 57 hours. The only food I had been able to force down over the proceeding three days was a bowel of soup. Weeks of violent coughing had made ordinary breathing a bitter process. At 29,028 feet up in the troposphere（气体对流）, so little oxygen was reaching my brain that my mental capacity was that of a slow child. Under the circumstances, I was incapable of feeling much of anything except cold and tired.
I’d arrived on the summit a few minutes after Anatoli Boukreev, a Russian climbing guide working for an American commercial expedition, and just ahead of Andy Harris, a guide on the New Zealand-based team to which I belonged. Although I just met Boukreev, I had come to know and like Harris well during the proceeding six weeks. I snapped four quick photos of Harris and Boukreev striking summit poses, then turned and headed down. My watch read 1:17 p.m. I’d spent less than five minutes on the roof of the world.
A moment later, I paused to take another photo, this one looking down the Southeast Eidge, the route we had chosen to go up. Training my lens（镜头）on a pair of climbers approaching the summit, I noticed something that until that moment had escaped my attention. To the south, where the sky had been perfectly clear just an hour earlier, a blanket of clouds now hid the peaks surrounding Everest. Later, after six bodies had been located, after a search for two others had been abandoned, after surgeons had removed the rotten right hand of my teammate Beck Weathers, people would ask why, if the weather had begun to worsen, had climbers on the upper mountain not observed the signs? Why did experienced Himalayan guides keep moving upward, leading a gang of relatively inexperienced amateurs — each of whom had paid as much as $65,000 to be taken safely up Everest — into an apparent death trap?
Nobody can speak for the leaders of the two guided groups involved, because both men are dead. But I can assure that nothing I saw early on the afternoon of May 10th suggested that a murderous storm was bearing down. To my oxygen-exhausted mind, the clouds drifting up the grand valley of ice known as the Western Cwm（西库姆*斗） looked so friendly and innocent in the brilliant midday sun, not different from the harmless puffs（喷烟）that rose from the valley almost every afternoon.
As I began my descent I was extremely anxious, but my concern had little to do with the weather: a check of the meter on my oxygen tank had revealed that it was almost empty. I needed to get down, fast.
(Note: Answer the questions or complete the statements in NO MORE THAN EIGHT WORDS.)
78. Where were the three climbers mentioned in the second paragraph from?
______________________________________________________________________
79. Besides the change of the weather, what else led to the expedition team’s falling into a death trap?
_______________________________________________________________________
80. The underlined phrase “the harmless puffs” in paragraph 4 refers to ______________
_______________________________________________________________________.
81. The author spent less than five minutes on the roof of the world and climbed down fast
because _______________________________________________________________.
【回答】
78. Russia and New Zealand.
79. Both the climbers and the guides.
80. the clouds drifting up the valley of ice
81. his oxygen tank is almost empty
知识点：科普环保类阅读
题型：阅读理解