Answer:
b. A deep, narrow river divides a population of hummingbirds.
Explanation:
Hummingbirds can fly across the river. The deep and narrow river can not separate a population of hummingbirds into two patches since hummingbirds from one side of the river can fly and reach to the other side of the river.
Without any geographical isolation, hummingbirds can continue to interbreed among themselves. The continued interbreeding would not allow their reproductive isolation and thereby would prevent the allopatric speciation.
Sunlight Water and good soil
Answer:
Burning sugar results in a chemical reaction
Explanation:
Flammability, odor, and density are just a few examples of characteristic properties of a substance. A chemical reaction occurs when molecules interact with one another and the molecules change. For example burning sugar results in a chemical reaction because the properties of cube B changed when it was burned. This change in solubility shows that cube B must be a different substance than cube A because of the chemical reaction that occurred when cube B was burned.
