I. humans migrated out of africa. ii. iii. humans spread rapidly south through north america. which of the following events belongs in slot number ii.? a. humans spread throughout north america and settled in regions. b. humans moved north from south america to canada. c. humans used ships to cross the pacific ocean. d. humans crossed the bering land bridge.

The correct answer is D. The Bering Land Bridge connects what is now Alaska to modern day northeast Asia. It would have allowed people to cross over into what we know as North America. Option A is incorrect, because humans would have to get to North America first before being able to spread throughout it. Option B is incorrect, because moving from South America to Canada would be moving north, not south. Option C is incorrect, because ships did not exist at the time of human migration out of Africa. 

4.a depression is the answer