简要说明味连的等级标准。

     We can see walls everywhere in the world. But the Great Wall of China is    1    of all. The Chinese
call it " The Ten-Thousand-Li Great Wall". It is    2    more than 6,000 kilometers long. It is 6-7 meters 
  3    and 4-5 metres from side to side. In most places, five horses or ten men can walk side    4    side
along the top.
     When you visit the Great Wall, you can't help wondering how the Chinese people    5    build such a
great wall thousands of years ago.    6    any modern machines, it was really very difficult to build it. They
had to do all the work by hand. It    7    millions of men hundreds of years to build it.
     The Great Wall has a history    8    over two thousand years. The men began to built the first parts of
it around two thousand seven hundred years    9   . Then Qin Shihuang had all the walls    10   . He
thought that could keep the enemy out of the country.
     Today the Great Wall has become a place of interest. Both Chinese and people from all over the
world come to visit it.