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. Given the paragraph above, please answer correctly the following question: Which city had people at decreased risk of developing asthma?

A: Berna

Problem: The prices of John's paintings started to rise immediately after the edition sold out. they used to cost $10 but now they sell for at least $200. john had 45 paintings in this edition. The prices of Mike's paintings are at $8 a piece, because his edition hasn't sold out yet. Mike's edition run was 250 editions. Given the paragraph above, please answer correctly the following question: Which painter sold a higher percentage of their paintings by today?

A: John

Problem: Sandra liked all creatures but loved to study frogs. Her sister Julie studied more about fish and butterflies. They both loved nature. Given the paragraph above, please answer correctly the following question: Which sister heard fewer frog calls during the day?

A: Julie

Problem: Rob is an amateur astronomer. Recently, he detected four asteroids, asteroid A, asteroid B, asteroid C, and asteroid D. Asteroid A and asteroid B are of the same mass, but asteroid A is farther from the earth than asteroid B. Asteroid C and asteroid D are at the same distance form the earth, but asteroid C has more mass than asteroid D. He also figured out that all of these asteroids have less mass than earth. Given the paragraph above, please answer correctly the following question: In classical theory, which asteroid would have stronger garvitational pull from earth, asteroid C or asteroid D?

A:
asteroid C