Which will you hear as the highest pitch? a sound wave with frequency of 10,000 Hz b sound wave with frequency of 30,000 Hz c sound wave with frequency of 15,0000 Hz d sound wave with frequency of 50 Hz

Paleontologists have found plant fossils deep within the layers of the north polar region. these leaf fossils have been labeled as to the rock layers they were found in, with the lower numbers being layers close to the earth's surface and higher numbers representing deeper layers. according to the numbers of these four leaf fossils, what might you infer?