What is the name of the raised field farming that the aztecs used to grow in the swampy lakes

Abird conservation society has a database of every bird spotted by members in the past year. to make this data part of a gis would require tying each sighting to

What is walt whitman's poem "when i heard the learn'd astronomer about?

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