Which of the following affects the surfaces of historical buildings made out of sandstone or limestone, and causes a reaction that forms a powdery substance that can be washed away by rain?
coal dustsulfur pollutantsvolcanic ashnone of these were mentioned in the reading

Explain how the density of ocean water is affected by temperature and how this results in major ocean currents distributing heat away from the equator toward the poles?

Which are evidence of the seafloor spreading? a. molten material b. magnetic stripes c. continental material d. drilled core samples e. ocean water samples

Ageologist is working in an area with exposed sedimentary rocks and finds a well exposed sequence of stratified rocks. as he works through a thick sequence of limestone, he sees abundant large clam fossils that produce an interlocking texture suggesting a reef, but within the limestone section these clams disappear and the overlying limestone is made up primarily of fragments of corals. he now moves 50 km away and finds limestones interbedded with shales, and the limestones contain the same clam fossils he had seen previously 50 km away. as he continues through this section, the rocks become entirely limestone, and the clams disappear again with coral fossils above forming a reef structure. he concludes