Questions: Exercise 2. Chuyển các câu sau từ thể bị động về dạng chủ động. 1. People visit the Great Wall of China every year. 2. Archaeologists have studied the pyramids of Egypt for centuries. 3. People are visiting the Colosseum in Rome right now. 4. People knew the Maya civilization for its advanced mathematics. 5. People were using the Great Wall of China for defense in ancient times.

To convert the given sentences from passive to active voice, we need to identify the subject performing the action and restructure the sentence accordingly. However, the sentences provided are already in active voice. Here they are:

1. People visit the Great Wall of China every year.

   • Active: People visit the Great Wall of China every year.

2. Archaeologists have studied the pyramids of Egypt for centuries.

   • Active: Archaeologists have studied the pyramids of Egypt for centuries.

3. People are visiting the Colosseum in Rome right now.

   • Active: People are visiting the Colosseum in Rome right now.

4. People knew the Maya civilization for its advanced mathematics.

   • Active: People knew the Maya civilization for its advanced mathematics.

5. People were using the Great Wall of China for defense in ancient times.

   • Active: People were using the Great Wall of China for defense in ancient times.

These sentences are already in active voice, with the subject performing the action clearly stated.