An epidemic occurs when an infectious disease spreads rapidly to many people. For example, in 2003, the severe acute respiratory syndrome (SARS) epidemic took the lives of nearly 800 people worldwide. disease outbreak happens when a disease occurs in greater numbers than expected in a community or region or during a season. An outbreak may occur in one community or even extend to several countries. It can last from days to years. Sometimes a single case of a contagious disease is considered an outbreak.
Quick Answer. Bitumen is primarily used to pave roads. It is a brown or black mixture of hydrocarbons, which is derived from petroleum. The consistency of bitumen varies from viscous to solid, and in its solid form, it is commonly known as asphalt. Continue Reading.
Sand and gravel are used for road construction, for mixing with asphalt, as construction fill, and in the production of construction materials like concrete blocks, bricks, and pipes. It is also used to make roofing shingles, used on icy roads in the winter, for railroad ballast, and water filtration.