Chuyển thành câu bị động

CHUYỂN BỊ ĐỘNG (PASSIVE VOICE)
1. People believe that this new teaching method is more effective than the old one.
=> This new teaching method

2. It is expected that some solutions will be made

=> Some solutions

3. People think that climbing is a dangerous sport

=> Climbing

4. It is rumoured that the towers were built very long ago

=> The towers