Answer:
Ho Chi Minh City, Shanghai, Karachi, Rangoon, Bangkok all lie on mainland Asia coastline.
For a start, Ho Chi Minh City, Karachi, and Shanghai are not the capital cities of their countries. Bangkok is not actually on the coast of Thailand nor is Rangoon actually on the coast of the Gulf of Martaban. So let's try again, shall we? Countries on the continent of Asia with capitals on the coast. Istanbul (Turkey), Beirut (Lebanon), Muscat (Oman), Abu Dhabi (UAE), Doha (Qatar), Kuwait City (Kuwait), Colombo (Sri Lanka), Singapore (Singapore), Jakarta (Indonesia), Tokyo (Japan),