Which of the following scenarios best explains the Columbian Exchange?

What is the function of the organelle labeled a in the diagram?

Cigarette manufacturers purposefully add to cigarettes in order to give them a particular flavor. a. cocaine b. carcinogens c. cigarette ashes d. a and b

Which of the following characterize the historical move toward urbanization? i. increase in pollution ii. increase in frequency of natural disasters iii. increase in incidence of infectious disease a. i b. ii c. i and ii d. i and iii e. i, ii and iii