Why did Cuba and the US stop being friends?

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

Describe the relations between the united states and other countries under the articles of confederation. 3-4 sentences

Which of these were effects of mass production techniques used during 1920s