How do you get retakes on a quiz

Which of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health? a. air quality data gathered by new instruments can be used to reduce exposure to pollutants. b. new technologies enable natural and human-made pollution sources to be located and monitored. c. air quality data gathered by new instruments can be used to predict trends in pollution over time. d. new technologies allow governments to make informed decisions about the regulation of pollution. (choose more than one)

Which action is good business etiquette? a. switching your cell phone off before you enter a meeting b. keeping your cell phone on low volume before you enter a meeting c. setting a pleasant ring tone on your cell phone before you enter a meeting d. setting a standard ringtone on your cell phone before you enter a meeting

What are "open-loop" and "closed-loop" systems