5 billion years ago ______ begins to form*1 pointPlanetsThe SunGalaxiesLightAtoms

1 billion years after the big bang the first ______ begin to form. (our notes said 500,000,000 years)*1 pointPlanetsStarsGalaxiesLightAtoms

Our solar system formed ______ billion years after the big bang.*1 point156914

The first ancestors of humans showed up about ______ years ago.A.10,000B.65 millionC.1 millionD.4.5 billio

When did life first appear on the planet?3.5 million years ago3.5 billion years ago2.1 million years ago2.1 billion years ago

The first animals arose on Earth approximately ______ years ago.Multiple choice question.570 million900 million140 million750 million