If there was more than one planet on each orbit, eventually they would collide with each other.
<span>1,040 mph
Dude just google it. </span>
The quote states that we should be using solar energy before our limited amount of naturally occurring oil and coal runs out. Meaning; we should be proactively working towards solar power rather than to wait for our resource to run out to start.
They are developed countries because the people there are healthy and educated.
