How did the last ice age affect human migration? a. it created land bridges where the ocean had once been. b. it required people to create new shelters. c. it required people to form larger communities. d. it required people to live closer together.

Its A i just took the quick check

answer; ///(b) it is composed of four protein chains and four heme groups;

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.