econamcis engineering hw I need it done in 3 hours

I uploaded a video for you to watch to answer these questions. However,  the 3rd Question you need to use the charts that I added ( lead SDS and Arsenic), for the fourth Question you need to google the Flint Water crisis in 2014 and how is it related to the case of the study. I need a paragraph for each question and support your answers with a good reason from the video