Effects of water restrictions?

Which of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health?

Read the article titled "trans-saharan migration routes to north africa and the eu: historical roots and current trends." why do tens of thousands of sub-saharan africans try to cross the mediterranean each year? how are these refugees commonly portrayed? (site 1)

Based on what you know about speed of light and sound, which come/comes first in a thunderstorm