四. 篇章結構： 2% (共10%)  When Qingzang Railway made its first journey from China to Tibet, the China claimed to have achieved an important record in the transportation history.   64     . However, the now famous railway track was built despite international concern for, among others, the preservation of wildlife and various engineering challenges.   65     . For the ground to remain frozen and stable, Chinese engineers built elevated tracks with foundations sunk deep into the ground and inserted vertical pipes that pass liquid nitrogen and cold nitrogen gas into the ground.   Additionally, as the air in Tibet is much thinner than the rest of the world, Chinese engineers also had to address the issue of altitude sickness in passengers who may experience shortage of oxygen.     66     . Last but not least, to prevent from interrupting the reproduction of certain wildlife habitat in Hoh Xil, also known as the untouched “no-man’s land,” the Chinese engineers have constructed a bridge-like safety channel at the Wudaoliang Basin.   67      . Based upon the same reason of wildlife protection, trains passing this zone are not allowed to blow their whistles.  68   . Yet, the long-term impact of this development still needs some time to observe it. In short, the railway is not only a convenient path to enter the place, but a more effective way for people who are interested in Tibetan culture to grasp more understanding about that. 
(A) Special passenger carriages are used, and oxygen is supplied to any passenger who needs it.
(B) With the speed of 100 km/hr, passenger trains on the Qingzang Railway will travel 4,064 km in distance and at a height of 4,000 meters sea level from China to Tibet in 48 hours.
(C) They even have to spread animal dung over it to encourage wild animals to pass through.
(D) The Chinese government says the Qinghia-Tibet Railway will bring economic and social progress to both China and Tibet.
(E) For one, 96 km of the track is built on frozen ground that becomes muddy during the summer.
【題組】64.