Answer:
A common measurement system allows them to make direct comparisons instead of having to know things like how much a certain animal weighs.
Explanation:
Got it off goo gle
The inner planets are made of rocks while the outer planets are composed of gas.
The inner planets are closer to Sun and are small in size while the outer planets are far away from sun and are larger in size
The sewing needle should float in the water if placed on a horizontal angle if I remember properly.
I hope this helps in some way.
I believe the answer is PREZYGOTIC isolating mechanisms