I would say that <u>a deadly water-borne microorganism in a city's water source</u> would most quickly devastate a human population, merely because a huge number of people uses this water for some kind of a purpose.
This simply means, when thinking about issues hat face the world today, instead of thinking about little issues that bug you or your town, think about issues affecting everyone in their daily lives, such as daylight savings and global warming. By acting locally, this means completing tasks no matter how big or small within your local area to help face these global issues. For example, acting against global warming on a local scale would be simply to educate the town or city as to what it is and how it can be prevented. Knowledge is power.
It is normally 100-120 so it is the first option. I hope this helps you.
Physical activity is like walking a dog and just doing day to day things with not alot of effort.
Birth defects can be caused wither by internal genetic factors or external factors like drugs, radiation, smoking,...
Dana, who is concerned about the possibility that her baby will have defects, may do the following tests: screening test, that will show if she might have child with birth defect and diagnostic test like amniocentesis (analyzing small amount of amniotic fluid from the area surrounding the baby) which is more than 90% correct.
