the soup have the larger surface from which to let off the heat? You
may now weigh only half as much as you will when you are fully grown,
but you already have much more than half as much size or surface.) 2.
What quality should all clothing material have, and why?

II. AN EARLY ROMP. 1. Which makes you more tired, to walk slowly, just
"lagging along," for about twenty minutes, or to walk briskly for the
same time? Why? 2. How do you make your muscles strong? What is your
heart made of? How can you make your heart strong? 3. Why do you need
a heart? 4. What is your _pulse_? Where can you easily feel a pulse?
Count the pulse of someone else for half a minute by a watch. Do this
accurately. How many beats would there be in a minute? Try this with
different classmates. 5. What do we call the tubes through which the
blood flows away from the heart? The tubes through which it flows back
to the heart? 6. What is happening to the blood on its "round trip"?
Where does it get the liquid food that it delivers to the muscles? Why
must the blood be carried away from the muscles?

III. FRESH AIR--WHY WE NEED IT. 1. If you were asked how we can tell
that air is everywhere, what could you say? 2. What do we call a thin
light substance like air? 3. What proof have we that the body needs
it? How does it get around to the different parts of the body? 4. What
is the body--its muscle, bone, skin, and all--made up of? How do these
cells use the air? Why do you need to breathe so often? 5. In the
candle experiment, is all the air under the glass used up? What is
used up? How can we compare a person in a closed room to the burning
candle under the glass? 6. What is the gas that we breathe out? 7. In
what three ways does the body "clean house"?

IV. FRESH AIR--HOW WE BREATHE IT. 1. Where are your lungs? 2. Draw a