1. It is believed that Ha Long Bay is a picturesque feature of Viet Nam.
Cấu trúc giả định với it
2. He says that I should go to Hue to visit the Citadel.
3. It is worth reducing the smoke and exhaust fume to prevent global warming.
worth + V-ing: đáng giá làm gì
4. It's a task to protect and preserve our man-made wonders for next generations.