Answer:D. Prothetic leg
Explanation:
All the other answer choices are still dreamt of by many scientists and engineers. but you always see people wearing prosthetic legs. D is the obvious answer.
Magma! I think and hope this helps
Answer:
I believe it is Genus, but I'm not sure.
Explanation:
Answer: Single cell organisms absorbed harmful gases from the air when they first formed
Explanation: