Which of the following has caused 100,00 year cycles of ice ages in the past?
a. an increase in sun spots
b. several major volcanic eruptions
c. changes in earths orbit and the tilt of its axis
d. continental drift

Which of the following is an example of a tissue on the digestive system a. the stomach b. smooth muscle that lines the stomach c. nerve cells in the stomach d. enzyme molecules in the stomach

The negative impacts of nonnative species generally outweigh the positive impacts

What is a limitation of using a chemical formula, such as c6h1206, to represent a compound? the chemical formula does not show the types of elements that make up the compound. the chemical formula does not show how the atoms are connected to one another the chemical formula does not show the number of atoms of each element in a molecule. the chemical formula does not show the chemical symbols of the elements in the compound