Explanation:
Option D is the correct option.
Answer:
Well , I think the answer is B
This represents a closed system,and one benifit is that the risk of passing disease between other species is lower than in open system
But still I prefer you to check it out in your book
Answer:
B
Explanation:
As the moon rotates around the Earth the angle of light given off from the sun changes.
Answer:
D
Explanation:
seismographs detect waves and vibration undergroud
