任务型阅读，根据短文内容，回答下列问题。
The Great Wall of China is one of the greatest wonders of the world. It is about 5500 miles long. The ancient Chinese began to build some walls around 600B.C. Qin Shihuang, the first emperor of China, joined the old walls together. From then on, people regarded the Great Wall as a symbol of the Chinese nation. Every year, many people find great pleasure in visiting the Great Wall But some sections of it are falling down. So people recently began to protect and repair the Great Wall.
How long is the Great Wall?
________________________________________________________________________
When did the ancient Chinese begin to build the walls?
________________________________________________________________________
Who joined the old walls together?
________________________________________________________________________
Do many people visit the Great Wall every year?
________________________________________________________________________
Why did people begin to protect and repair the Great Wall recently?
________________________________________________________________________