What is the main cause of extinction in the last 11,000 yrs?

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

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Which level of taxonomy has the fewest organisms?