Read the passage, and choose the correct answer A, B, C or D for each question.

Câu hỏi :

Read the passage, and choose the correct answer A, B, C or D for each question.

      The Complex of Hue Monuments is a UNESCO World Heritage Site and is located in the city of Hue in central Vietnam. Hue was founded as the Viet Nam capital city by Gia Long, the first king of the Nguyen Dynasty in 1802. It held this position for thirteen Nguyen kings until 1945.

      The massive complex features hundreds of monuments and mins, such as the Forbidden Purple City, once the residence of the royal family and badly damagedduring the Vietnam War. the Imperial City, royal tombs, the flag tower, pagodas, temples, a library and museum.

      Hue, located on the banks of the Huong River, (also known as the Perfume River) is about a hundred kilometres north of Da Nang. Among the most impressivemonuments in this former grand imperial capital are the Ngo Mon Gate of the Imperial City which once was exclusively used by the royal family and their servants and soldiers, the tomb of Emperor Minh Mang as well as the tomb of EmperorTu DuC. In fact, many of the monuments surrounding the royal buildings were constructed in the early 19^th century and were modeled after Beijing’s Forbidden City. The wall that surroundings the citadel is six metres high and two and a half kilometres long.

      The historical complex is known not only for its rich architecture but also for its beautiful landscape setting. Overall, the site is quite spectacular. Avoid Hue between October and December as it gets most of its rain from the northeast monsoon during that period. This small city is also famous for its Imperial-style cuisine.

1.   The Hue Citadel needs the work of restoration because of                      .