When a frying pan is placed on an electric stove top, heat energy is transferred from the burner to the pan by OPTIONS:
- convection.
- radiation.
- conduction.
- insulation.
A: conduction.

Juvenile diabetes is a disease caused by the body's inability to create insulin. The body's white blood cells attack the pancreatic cells that produce insulin. This type of disease is known as OPTIONS:
- a cardiovascular disease.
- an infectious disease.
- a digestive system disease.
- an autoimmune disease.
A: an autoimmune disease.

Most underground caves are formed by the action of water on OPTIONS:
- granite
- limestone
- sandstone
- shale
A: limestone

Variation in which property between water at different temperatures contributes most to the formation of horizontal ocean layers having distinct temperatures? OPTIONS:
- density
- viscosity
- turbidity
- acidity
A:
density