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.
Mountains are formed by slow but gigantic movements of the earth's crust (the outer layer of the Earth). The Earth's crust is made up of 6 huge slabs called plates, which fit together like a jigsaw puzzle. When two slabs of the earth's crust smash into each other the land can be pushed upwards, forming mountains. Many of the greatest mountain ranges of the world have formed because of enormous collisions between continents.