阅读下面短文，根据所读内容在文后的第76至85小题的空格上填上适当的单词或短语。每空不超过3个单词。
The Gobi is one of the world’s great deserts. The desert basins of the Gobi are bounded(边界限制) by the Altai mountains and the grasslands of Mongolia on the north and by the Tibetan Plateau(青藏高原) to the southwest.
The word Gobi means “desert” in Mongolian. The Gobi is most famous in history as part of the great Mongol empire, and as the area of several important cities along the Silk Road.
The Gobi measures over 1,600 km southwest to northeast and 800 km from north to south. The desert is widest in the west. It covers 1.3 million square kilometers in area, making it one the largest deserts in the world. Much of the Gobi is not sandy but is covered with rock. The desert holds so many animals, such as Gobi bear, the wild camel and the black-tailed gazelle(羚羊), and is sometimes visited by wolves. The Kerulen River is the Gobi’s largest stream. It flows into small salt lakes or disappears into the sand. Nearly all the soil here has been removed by the north-westerly winds. The sand and wind storms are common. The Gobi has cold winters and short, hot summers. The Gobi is crossed by a high way, which links Ulaanbaata with Jining, China.
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77	one of the world’s great deserts, the Gobi,    78    by the Altai mountains and  on the north and by the Tibetan Plateau to the southwest, lies in the northwest of China.
79	the word of its name came from Mongolian. It acted     80    an important part in the history of great Mongol empire, which was famous for the Silk Road.
size	the west of the desert is widest. It covers1.3 million square kilometers,    81     over 1,600 km southwest to northeast and 800 km from north to south.
animals	many animals live on the desert, such as Gobi bear,    82    and the black-tailed gazelle, and is sometimes visited by wolves.
83	the Gobi    84    rock mostly, and the soil has been moved by the north-westerly wind. The largest stream is Kerulen River, which flows into    85     at last. The sandstorm, cold winters and short, hot summers are very common.