用一个符合上下文的单词填空。这是B2 First FCE阅读第二部分。有关如何解决任务的提示和解释，请访问 B2 FCE阅读第二部分
The Great Wall of China
[0] The Great Wall of China is (1) (世界上最著名的地标之一). It was built over many centuries to protect the Chinese Empire (2) (免受入侵). Contrary to popular belief, it is not a single continuous wall, (3) (而是一系列的墙和防御工事). It stretches (4) (跨越数千公里) across mountains and deserts. Millions of tourists visit the Wall (5) (每年). However, certain sections are (6) (面临倒塌的危险) due to natural erosion and human activity. The government has (7) (采取了措施) to preserve this incredible monument so (8) (以便) future generations can enjoy it.