What is the meaning of "spl", "aspl", and "pl" in boy scout of america?

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

Read the excerpt from the history of herodotus, book 2. egypt . . is an acquired country, the gift of the river. this quotation from herodotus, a greek who traveled in egypt, is about how the nile river enabled ancient egyptian civilization to develop and succeed. what specifically was the river’s gift? fertile soil fishing stocks defensive capabilities drinking water

What new concept did the the american revolution introduce into the world