<span>If the middle groin was not constructed then there would be more erosion between the first and last groin. The middle groin must be constructed in order to fix the erosion between the two groins. If the first or the last groin was not constructed then the erosion will be less compared to the middle groin.</span>
Answer:
This is a rather complicated thing to explain so I'll try my best. To put it in simple term the sun has whats called a SOI (sphere of infleunce) and anything inside of this is effected by the gravity of that planet or sun in this case. The earth is inside of this sphere of influence. The earth has a constant velocity that is making it move away from the sun but since it's in the suns SOI the path in which the earth moves is changed in a way that causes it to spin around the sun. The same thing is happening with the moon. I'm not 100% sure on this but I think the reason the moon does not just fly away towards the sun is because it is closer to earth and is more effected by earths SOI. Hope this cleared things up for you.
Answer:B). Cell membranes are composed of a lipid bilayer.
Explanation: A membrane is a lipid bilayer that surrounds the cell. Lipids have two parts: the fatty acid chain (the tail) and the phosphate group (the head).
The phosphate head groups are polar, face outward and interact with the outside environment of the cell. The fatty acid chain is hydrophobic and nonpolar, face each other in the bilayer thus forming a hydrophobic fluid interior.
The hydrophobic nature of the bilayer interior makes the membrane to permit only nonpolar and hydrophobic molecules to pass through the cell membrane. This is the reason the membrane allows only molecules that dissolve in the lipid bilayer to pass through to enter or leave the cell.