4. Volcanic rocks are often classified based on color, as follows: rhyolite andesite basalt grey, pink dark grey black The color of volcanic rocks is partly related to the proportion of silicon dioxide they contain. Which of the rocks listed on the Data Sheet tend to have the highest proportion of silicon dioxide? The next highest? The lowest?

answer: 45

explanationyou have to add as well to be it could be

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;

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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.