Flu-like Illness. One of the earliest HIV symptoms in men is a severe 'flu-like' illness, known as the 'seroconversion illness.'. Seroconversion is the point in time where a person's blood is converted from being HIV negative to HIV positive, by the production of antibodies.
Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arÃªtes, and bowl-shaped cirques that can contain lakes.
Some deserts located by mountains and are caused by the rainshadow effect. As air moves up over a mountain range, it gets cold and loses the ability to hold moisture -- so it rains or snows. When the air moves down the other side of the mountain, it gets warmer.