What accurately describes a letter written during the time a historical event occurred

Marine exptoration of oil uses seismic waves to locate oil in the seabed. what is a negative impact from seismic waves on the aquatic ecosystem of the ocean? a.seismic waves kill microoganisms b.seismic waves disrupts the sand and causes seafloor erosion c.seismic waves have virtually no adverse affects on marine life d.seismic waves damage the sonar that dolphins and whales use to orient themselves underwater

Approximately how many americans, from both the north and the south, were killed in battle during the civil war?

Which kind of map you would be used to show population density in the countries of the world