Answer:
Growth is biggest obstacle to cleaner air. The Environmental Protection Agency's new standards for ground-level ozone and particulate matter have received lots of media attention in recent weeks.
Explanation:
hope this helped it was on my school too
Students in the US spend a total of 5 days in school (highschoolers)
D. Obtaining scarce resources
The Mongol Empire split into
✔ four khanates
after the death of Ögedai Khan.
Explanation:hope it helps ;]