The fossilized teeth of ancestors of the modern horse have grown progressively larger and flatter over the past 60 million years. which of the following is the best explanation for the changes seen in horse tooth structure over time?

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

Temperatures in ponds and lakes vary by season. select the best answer from the choices provided t f

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.