Agroup of ants attack a cicada, feed on it, and kill it, even though it is much larger than the ants. which kind of relationship do the ant and the cicada share?

The relationship between the ant and the cicada is Parasitism --- One organism benefits, by hurting the other organism. I hope that this is the answer that you were looking for and it has helped you. Have a nice day.

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.