John has been hearing about climate change for last couple of years. He wants to understand the science behind climate change. For that, he picked up two eras in earth's history, era A and era B. Era A was hundred thousand years ago, and era B is in the present day. He now wants to compare these to eras to understand the change in climate better. Which era would have more carbon dioxide in the atmosphere, era A or era B?
Ans: era B

Two chickens are living on the same farm. Chicken A has just been infected with a parasite, but Chicken B does not have the parasite. Chicken A probably got it when it went swimming out in the old stagnant lake while the other chickens were sleeping. Which chicken is less likely to get sick?
Ans: Chicken B

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 increased risk of developing asthma?
Ans: Shanghai

Keith was a studying for his chemistry exam. He got interested in solubility of different substances. For that, he conducted five tests, test A, test B, test C, test D, and test E. in test A, he used some liquid solute in a solvent in room temperature. Then in test B, he increased the temperature. In test C, he used some gaseous solute in a solvent in room temperature. But in test D, he increased the temperature. Finally, in test E he replaced the solvents in each of the earlier tests with water. In case D would the solute be less or more soluble than case C?
Ans: less