• A definition clue defines the word in the text. Some words that signal a definition clue are called, is/are, and this means.
EXAMPLE Veins are blood vessels that carry blood back to your heart. • A restatement clue says the same thing in a different way. One word that signals a restatement clue is or.
EXAMPLE Use a microscope to examine, or study, cells.
Use the context clues to figure out the meaning of each underlined word.
1. Villi are fingerlike structures that line the small intestine.
2. Digestive juices break food into sources of nourishment, or nutrients.
3. The diaphragm is a sheet of muscle beneath your lungs.
4. Inside each lung are millions of air sacs called alveoli.
HEALTH & SCIENCE
Do an experiment to learn more about the respiratory system.
1 Find Breathing Rates Count how many breaths you take in one minute. Write down your results on a piece of paper. Next, jog in place for one minute. Then count how many breaths you take in one minute. Write down those results.
2 Graph and Discuss Results How did your two breathing rates compare? Why do you think they were different? With your class, make a bar graph that shows everyone’s results. What were the most common breathing rates?
After Exercise
Resting