Question 5. A- it grew from tiny village to a boomtown
question 7. false
question 8. false
Homeostasis is the attempt to maintain stable conditions (particularly in an organism). It is done by using feedback loops (positive and negative).
A virus structure can be on of the following: icosahedral, enveloped, complex and helical. These viruses can appear to in a shape but a closer, more steady look reveals that they are actually icosahedral.
PROS: It dissolves in water and lowers the freezing point of water so a lower temperature is required for ice to form. This makes the road less treacherous for vehicles. Road salt is usually cheap and readily available. Since salt is already a constituent of sea water, it does not cause pollution when washed away.
CONS: Salt dissolved in water is corrosive to metal. A metalled road surface may eventually be attacked by the corrosive, leading to damage of the surface. The salt solution is splashed on to the bodies and into the engine parts of vehicles and, unless properly protected, the metal parts of the vehicle will become corroded. Salt solution is a good conductor of electricity so it could under certain circumstances affect the electrical circuits within vehicles. When the salt solution dries out it leaves a deposit of white salt on the surface. The spreading of road salt is often carried out by specially equipped vehicles, so there is a cost incurred in salt spreading. Usually salt is mixed with grit.
Limestone is composed largely of the minerals calcite or aragonite. Some limestones do not consist of grains and are formed by the chemical precipitation of calcite or aragonite. This is how limestone can be classified as chemical.
