What does an unconformity in a sequence of rock layers reveal about geologic history?
a.
a rock layer must have turned upside down.
b.
a layer of rock might have eroded.
c.
the layers must cover hundreds of square miles.
d.
the layers must have been deposited very quickly.

Answer asap! the weather patterns on earth are shown in this image. explain why there are convection currents; why there are hotter and colder parts of earth.

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.

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.