The sun a. will become a red giant within two to three million years b. is in its main sequence, which willlast thousands of years c. is in its main sequence, which will last billions of years. d. will explode as a supernova after its main sequence

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