阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
A
72 hours in Beijing
Traveling to China is no longer a luxury for many foreign passport holders. The Chinese government has permitted a 72-hour visa-free policy that offers access to visitors from 53 countries including the US， France and Austria. Let's start with the capital of China， Beijing. Here's a pick of the best in Beijing!
Mutianyu Great Wall
Your trip to Beijing isn't really complete without seeing one of the “New Seven Wonders of the World”， the Great Wall of China. The Mutianyu section of the Great Wall is by far the most well-preserved of all. Taking a one-hour bus ride， Mutianyu would be your ideal location for a half-day of hiking away from the large crowds in the city. Also， the authorities have allowed tourists to paint graffiti on a specific section of the Great Wall since 2014. The Great Wall was designated（把……定名为） a UNESCO World Heritage site in 1987.
Summer Palace
Located in northwestern Beijing， the Summer Palace is by far the city's most well-preserved royal park. With its huge lake and hilltop views， the palace offers you a pastoral escape into the landscape of traditional Chinese paintings. The Summer Palace was added to the UNESCO World Heritage List in 1998.
798 Art Zone
This would be on the top of my list! Named after the 798 factory that was built in the 1950s， the art zone is home to various galleries， design studios， art exhibition spaces， fashionable shops and bars. You could easily spend half your day wandering around the complex， feeling the contrast of the present and the past.
Sichuan Provincial Restaurant
While in Beijing， apart from trying the city's best-known Peking duck， the Sichuan provincial restaurant is one of places where you can enjoy regional delicious food. It offers one of China's eight great cuisines， Sichuan Cuisine， which ranges from Mapo tofu to spicy chicken.
21. How does the author describe Mutianyu Great Wall?
A. Tourists need a half day to arrive there.
B. Tourists are allowed to paint graffiti anywhere.
C. It is the most well-maintained part of the Great Wall.
D. It was named a UNESCO World Heritage site 20 years ago.
22. Where would you go first if you were the author?
A. Mutianyu Great Wall. B. Summer Palace.
C. 798 Art Zone. D. Sichuan Provincial Restaurant.
23. Who is the text intended for?
A. The tourists who prefer to travel for free.
B. The foreigners to stay in Beijing for 3 days.
C. The visitors coming from every corner of China.
D. The foreigners coming to Beijing for the first time.
