Bill once had a blue car that was in the shop more than it was on the road. Since then he will not even consider owning a blue car. Bill's aversion to blue cars is
an example of:

Apart of an ecosystem that can restrict the growth of a population is referred to as

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures

Several billion years ago which gas was the least prevailant in the atmosphere