<span>Carbon, Hydrogen, Nitrogen, and oxygen </span>
Well first i just wanna say that life on mars has been discovered,not little green men but Bactria found on the surface and small traces of water have been found as well. some forms of life need little water to survive (like bacteria) but they still need water so yes there is water on mars the question is will we find it.
The concept map is not shown
You need to do speed divided by time
A. Development of transportation
