Nations governed only by one central government are known as systems

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

June 19 is often a holiday in texas. it is emancipation day. what important event happened on emancipation day? a) it marks the end of slavery in texas. b) it marks end of the texas revolution. c) it marks the day texas became a state. d) it marks the last battle of the texas revolution.

President franklin d. roosevelt was born in 1882 in new york. which number on the map represents the state of new york?