David was studying human history. He selected two specific eras of human history, era A and era B. Era A was before humans had invented agriculture. And, era B was after the invention of agriculture. He noticed that human societies had changed dramatically after the invention of agriculture. Did era B have higher or lower brith rate than era A?
Ans: higher

Mary was from a family that forbids all vaccinations. She never got any vaccines and developed immunity the hard way by getting many respiratory diseases. Ann got all here vaccines done in time and at the proper age. Which person experienced no common cold?
Ans: Ann

Timber village started a channelization process by draining all the swamps near their village. Hill village situated 10 miles to the south, left their swamps untouched. Which village experienced no decline in waterfowl species?
Ans: Hill

Sarah and Sophie are sisters living in two different cities. Sarah lives in a very rural area with hardly any air pollution. Sophie lives in a heavily industrialized urban area with many factories and people driving cars to their destinations. This all leads to Sophie's city having a large amount of pollution going into the atmosphere. Who is less likely to die from air pollution?
Ans: Sarah