The body’s first line of defense against infection includes the . The second line of defense is the , and the third line of defense is the .

Diego conducted an experiment to find out what kind of ball bounces the highest when dropped from a five-foot platform. he used a golf ball, a tennis ball, and a soccer ball. he dropped each ball from the balcony once. diego recorded his observations after each drop. what can diego do to best improve the reliability of his results? a) drop each ball from the platform three more times b) record his observations in more than one unit c) write at least two scientific questions after the experiment is complete d) share his results with other people who have done similar experiments you for the !

What happens to the average kinetic energy of water molecules as water freezes?

How has biodiversity on earth changed over time?