Problem: Tommy sets two pots of water, Pot A and Pot B, on the stove and sets each burner to a different temperature. Tommy is unable to see what the temperatures of the burners are though. He sits around patiently and waits until he notices that Pot B's water is beginning to vaporize, while Pot A's water is not vaporizing. Which pot has not reached its boiling point?

A: Pot A

Problem: Year 2022 would be an interesting year when three comets would get scientists' attention - Comet A, Comet B, and Comet C. Comet A and C are very faint, but Comet B is very bright. Comet A would enter the inner solar system on February 10, 2022 and leave the inner solar system on February 20, 2022. Comet B would enter the inner solar system on February 18, 2022 and leave the inner solar system on February 26, 2022. Comet C would never enter the inner solar system. On Which date Comet B's dust would start reflecting sunlight?

A: February 18, 2022

Problem: Two sister cities had different environments. Shanghai had big problems with air pollution while Berna took very good care of the surrounding environment and air quality. Which city had people at decreased risk of dying from other diseases?

A: Berna

Problem: Dan and Joe studied animals for biology class. Joe had to study predator animals, while Dan studied herbivores and grazers. Which student learned less about the balance of organisms in an ecosystem?

A:
Joe