The esophagus is a tube in which food is pushed from the mouth to the stomach. as the food is pushed through the esophagus, it becomes more compact. this is-- a) physical change only

b) chemical change only

c) both physical and chemical

d) neither

help sdusdj i got c but it was wrong so now i think its a

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

one part of the electromagnetic spectrum that arrives on earth as solar radiation from the sun is the visible spectrum. wavelengths of the visible spectrum combine to form what we refer to as

answer - d) ultraviolet radiation.

violet /   380–450 nm / 668–789 thz

violet is number 1 in the chart of visible light.