I think the cytoskeletal protein that helps a cell maintain its shape is actin.
Answer:
Surface water <---> river
Ground water <------> well
Water vapour <------> atmosphere
Glacier <-------> ice
Explanation:
Mastication is just a fancy way to say chewing. Since nothing chemical is going on and the food is just being chewed, the answer is physical.
Answer:
Grey and White Matter.
Explanation:
When looking at an image of trasnverse section of the spinal cord the grey matter is almost butterfly shapped and it has the central canal in the middle. The white matter is surrounding the butterfly shaped, grey matter.