题目内容：

The Great Wall of China is more than 6,000 kilometres long. It winds 1. (it) way from west to cast, across deserts, over mountains, through valleys 2.at last it reaches the sea. The Great Wall has a history of over twenty centuries. The first part of it 3. (build) during the Spring and Autumn period. During the Qin Dynasty, 4. (keep) the enemy out of his empire, Emperor Qin Shi Huang had all the walls 5. (join) up. Thus, the Great Wall came into being. The Great Wall is wide enough at 6.top for five horses or ten men to walk side by side. Along the wall are watchtowers, 7.soldiers used to keep watch. Fires were lit on the towers as a 8. (warn) when the enemy came.

It was 9. (extreme)difficult to build such a wall in the ancient days without any modern machines. All the work was done 10.hand. Thousands of men died and were buried under the wall they built. The Great Wall was made not only of stone and earth, but of the flesh and blood of millions of men.