1 . Sitting back in my seat, I can’t quite believe that I’m about to travel along the railway that many foreign experts claimed was “impossible”. The train has been racing along steadily since it left Xining. All this time, the song “Sky Railway” has been_________inside my head. The words “railways like massive dragons are winding among the mountains” seem particularly_________as I travel across the “roof of the world”.

I was one of the people who came from all parts of China to work on this railway._________years to complete, the Qinghai-Tibet Railway is a record of all of our efforts to_________the most difficult engineering challenges. How to_______the delicate ecosystem was among the top concerns.

The first_________to catch my eye is the splendid Qingshuihe Bridge, the world’s longest bridge built over permafrost. Look! A group of Tibetan antelopes is moving under the bridge, with some stopping to eat grass at their_______. Thirty-three passages have been built under the railway to allow the animals to move safely and freely in their natural_________. Wild animals such as these Tibetan antelopes have now been using these_________for years. They seem totally__________that we are speeding past at over 100 kilometres an hour.

To prevent__________to wetlands and grasslands, 675 bridges with__________about 160 kilometres were built between Golmud and-Lhasa. We even moved 140,000 square metres of wetland to a new area in order to protect its distinct ecosystem.

The journey has been flying by, and before I know it, we have reached Tanggula Station.__________at over 5,000 metres above sea level, this is the__________railway station in the world. In locations such as this, the thin air,__________weather and high levels of UV radiation presented perhaps the greatest__________ for railway workers. To make sure we stayed__________, several oxygen-making stations were constructed. We were also able to enjoy__________breaks in lower areas.

As we pass Cuona Lake, I feel a sense of pride and achievement. Using thousands and thousands of sandbags, we built a twenty-kilometre wall along the lake to protect it from construction waste. Cuona Lake is so close to the railway that I want to__________and touch its pale blue mirror-like surface. Water birds playing in the lake, and cattle and sheep wandering the grasslands bring the scenery to life.

The Qinghai-Tibet Plateau has been attracting people’s admiration for centuries. Now, thanks to our efforts, passengers from all over the country have been enjoying these magical landscapes. I am proud that we built our “impossible” railway, and did so with the care that the environment__________. It truly is an extraordinary “Sky Railway”.