1. What is the East Sea (Biển Đông) in the context of Vietnamese marine geography?
A large marginal sea of the Pacific Ocean, approximately 2.5 million km² in area, connecting the Indian Ocean and the Pacific Ocean
Explication
The East Sea (Biển Đông) is a large marginal sea of the Pacific Ocean, covering about 2.5 million km², and plays a crucial role as a maritime corridor connecting the Indian and Pacific Oceans, bordering several countries including Vietnam.