Which statement describes the law of superposition? O Sedimentary rocks were originally in horizontal layers.
In horizontal rock layers, each layer is younger than the one below it.
Rock layers must be in existence before something can happen to them.
O Rocks that are not in horizontal layers were shifted by some geologic event.

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

How is the carbon cycle related to global warming ?

Which term describes a normal value for something in the body? a. homeostasis b. set point c. feedback loop d. integration center