Shànghǎi gǎngkǒu shì shìjiè shàng zuì fánmáng de gǎngkǒu zhīyī.
Shanghai's port is one of the busiest ports in the world.
Tips
usage
港 alone can mean 'port' or refer to Hong Kong (香港 Xiānggǎng). 港口 specifically means the physical port/harbor. 机场 (jīchǎng) is an 'air port' - 空港 (kōnggǎng) is a more literary equivalent.