In which of the following relationships is one species benefitted and the other is unaffected? a. parasitism b. predator-prey relationship c. commensalism d. mutualism

Hey!

Parasitism means: Where one benefits while the other is harmed. 

Commensalism means: Where one benefits and one is unaffected and unharmed. 

Mutualism means: Where both organisms benefit from each other. 

Predator-prey relationship means: Where a predator catches a prey. 

So, the correct answer is C. Commensalism. 

If you get a map and put the countries a states all together it forms all one piece you can also tell because of the earth quakes

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.