How does sediment form?

a. loose material is compacted by pressure
b. weathering breaks down rocks and other materials
c. molten rock cools below earths surface
d. chemical changes cause sediment to cement together

your answer is "the 1950's"

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what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.