Answer:
A options hydrogen
Explanation:
valence outermost element is hydrogen.
Nitrogen fixation. most nitrogen fixation is performed by certain kinds of bacteria . Some of this bacteria live in bumps called nadules (NAHJ oolz) on the roots of certain plants.
Answer:
D. It can be analyzed and shown to be reliable or un-reliable.
Explanation:
Trying the model out here on earth gives them a chance to observe what it would look like out there.
This will give them the chance to analyze the effectiveness of the rover and see if it can be reliable or not and if necessary adjustments should be made.