Which of these is an example of selective breeding?

A: Cutting a stem from a plant so that a new plant grows from the stem
B: Taking a skin cell from a sheep and making an exact clone of the sheep
C: Replacing DNA of a plant with DNA that allows the plant to grow in little water
D: Selecting two horses and having them mate in order to produce stronger offspring

One statements is an example of a scientific observation. another statement is an example of a scientific explanation. identify the correct statement for each category to illustrate how scientific explanations are inferred from scientific observations.

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

When a gasoline engine burns gasoline, what type of chemical reaction is occurring?