Task: Question Generation
Input (English): Background Paragraph: Marine pollution is a generic term for the entry into the ocean of potentially hazardous chemicals or particles. The biggest culprits are rivers and with them many agriculture fertilizer chemicals as well as livestock and human waste. The excess of oxygen-depleting chemicals leads to hypoxia and the creation of a dead zone.Marine debris, which is also known as marine litter, describes human-created waste floating in a body of water. Oceanic debris tends to accumulate at the center of gyres and coastlines, frequently washing aground where it is known as beach litter. 
Story: Bird city had may economic ties with Pine city. Pine city was located in the mountains, and was inhabited by nature lovers and people that protected the environment. Bird city was situated on the banks of a large river flowing into the sea. They relied mostly on conventional agriculture and used fertilizer for their crops.
Output (English): Which city contributed more to the creation of dead zones?