What was the main cause of sulfur-dioxide pollution in Hanoi, according to the article? why did vietnamese painters use uncommon things in their paintings?
Thought to be from the widespread use of coal cooking fires in Hanoi
What was the main cause of sulfur-dioxide pollution in Hanoi, according to the article?why did vietnamese painters use uncommon things in their paintings?Thought to be from the widespread use of coal cooking fires in Hanoi