What is the origin of cold, wet air masses? A. Over water in tropical zones
B. Over land in polar regions
C. Over land in tropical areas
D. Over water in polar regions

This is one type of line graph in which the independent variable is time plotted on the x axis and the dependent variable, also numerical, is plotted on the y axis.

Estimate the magnitude of the electric field due to the proton in a hydrogen atom at a distance of 5.29×10 to the power of −11 m, the expected position of the electron in the atom.

Emergent properties of living systems are defined as properties that .