There was no life on Earth for the first billion years because the atmosphere was not suitable for life. Earth's first atmosphere had lots of water vapor but had almost no oxygen. Later, frequent volcanic eruptions put several different gases into the air.
OK. First, there's the heart. Then there's the blood vessels. The arteries. Then the veins. And then there's the capillaries. <span />
Re: A car driver automatically brakes if a child dashes across the road.
<span>This is called a .............................................. reaction.
answer: reflex</span>
I think it's B. one who has many personality traits
Energy
they could be producers or consumers
producers make their own food/energy
consumers get energy from other living things
