Giraffes evolved over many generations to have long necks. giraffes that had longer necks were more likely to survive than giraffes with shorter necks because they had better access to food. this is an example of

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a. an ionic bond is formed between the oxygen and carbon atoms. b. four valence electrons are shared. c. two valence electrons are shared. d. valence electrons are shared between oxygen atoms.