Which of the following substitutions can reduce air pollution?

a.) using a bike instead of a car
b.) using dumps instead of landfills
c.) using coal instead of oil
d.) using fireplaces instead of a wind farms

Among the choices given, only the first choice, "A. using a bike instead of a car", can help reduce air pollution. This is because a great percentage of the total air pollution is attributed to the emissions from the cars and other vehicles. 

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.

Ican not answer this question since it does not have enough information