Can you please tell me the Answers for number 6 and 7 please

Which evidence is most likely used to indicate the beginning of solar system formation? a. materials combined to form a mass. b. materials were pulled together by gravity. c. water condensed and collected to form oceans. d. different species of microorganisms lived on earth.

Southeast asia relies on its many because of the volcanic, mountainous terrain. a. highways c. rivers b. airports d. lakes

Identify the youngest layer in the figure ( have to click one letter)