Scientists believe the increase in disasters is due to a combination of natural and human-caused factors. list and describe at least one natural factor and one human-caused factor.

Could someone . i have tried to solve myself but my calculation is off

Each neuron shown in this figure innervates a group of muscle fibers. what is the term for a group of muscle fibers innervated by a single neuron?

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