Which of these events happens first in earth's polar regions?
a. the dense water sinks.
c. water molecules move closer together.
b. the water travels as a deep current.
d. cold air chills water molecules.

Iguess i would say diagrams would be most difficult subject too correct

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.

Exposure to solar flares would be the correct answer