What two things must be present for a mechanical wave to form? a. Time & Energy
b. Energy & Resistance
c. Energy & a Medium
d. A Medium & Time

This is the diveristy of ecosystems natural communites and habits it is the variety of ways that species interact with each other and their environment

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased

Which statement best describes the role of religion and culture in ancient medicine?