The Beginning of the Phanerozoic Marks an Important Event in Animal

Q26: The age of Earth is about _.<br>A)195

Q27: Which one of the following represents the

Q28: Due to a virtual absence of land

Q29: Earth's primitive atmosphere evolved from gases _.<br>A)collected

Q32: Modern human evolution takes place during the

Q33: On continents, large "core areas" of Precambrian

Q34: The _Eon spans about 88% of Earth's

Q35: As the solar system began forming, the

Q36: By the_ period, large tropical swamps extended

Q83: The development of _,organisms that reproduce sexually