The correct answer is: It describes how China's government has used physical and virtual walls to protect itself through the history.
Explanation:
The main idea of the article ''Like the Great Wall, the Great Firewall may not be able to protect China's government forever" describes the systematic separation of China from the rest of the world by using physical and virtual walls to protect themselves from foreign influences. This statement refers to the fact that China blocks almost all foreign media, human rights groups or websites which considers harmful for its citizens.
These walls were a great way of defense through history, but, today, with today's technology development, those walls probably will not be strong enough to protect the country from foreign influences and new trends.
