Acity is considering switching to geothermal power for their electricity needs. which of the following is an advantage of this plan?

it is commonly used across the entire united states.
it uses less land area than gas power plants.
it uses water to power large turbines.
it in inexpensive to build.

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3