-rotate
There are many
different kinds of soils. Different soils have
different
types of rock and minerals in
them. Some soils have more water in them
than
others.
Some
soils
might
have
more
plant
and
animal
material
in
them, too. Different
kinds of soils are found in different parts of the
world.
There are several kinds of soils
found in the United States. In some areas,
the soil has a lot of clay. Other soils
are very sandy. Loam is a kind of
soil
that has a good mixture of clay and sand. In some
places, soil layers
are very thick.
Lots of plants grow in places with a thick soil
layer. In dry
and
windy
places
soil
layers
are
much
thinner.
Layers
of
soil
on
mountains are thin because gravity
pulls the soil downhill. The type of
soil in a particular place affects what
kinds of plants can grow there.
22.
Crisis
Life
is
a
contest!
Who
will
win?
A
bluebird
and
sparrow
both
compete
for
space
to
build
their
nests.
A
fast-growing
maple
tree
and
slower-
growing
dogwood compete
for
the
sunlight
they
both
need.
Oil
competes
with
coal
and
nuclear
power
as
an
energy
source
for
electric
power plants! There
is a problem. There is a limited amount of space
for
birds, sunlight for trees, and
energy for people! If we do not cut back on
our uses of some of our resources,
someday they will be gone! How can
we
use energy today and know we will have enough to
go around in the
future?
We
can
choose
alternate,
or
replacement,
energy
resources.
It
takes
the
earth
millions
of
years
to
create
coal,
oil,
and
gas.
They
are
nonrenewable resources. Solar energy,
wind energy and water energy are
renewable resources. It takes the earth
millions of years to create coal, oil,
and gas. They are nonrenewable
resources. Solar energy, wind energy and
water
energy
are
renewable.
What
other
ways
can
we
conserve
our
resources? How can we make sure there
is always enough to go around?
23.
America’s Worst
Surprise
December 7,
1941 was one of the worst days in American
history.
Nearly all Americans who are
old enough to remember that day can
still
remember what they
were doing at the moment they heard
“the news”.
The news was that America
had been attacked! Shortly before 2:00 P.M.,
a radio dispatch came into Washington
from Honolulu, Hawaii. “Air Raid,
Pearl
Harbor
—
This is
no drill.” Japanes
e planes had begun an
attack on
the
largest
American
military
base
in
the
Pacific.
They
first
destroyed
planes on the ground. Then they bombed
the ships in the harbor. No one
had
expected the attack. So no one was prepared for
it. And it did not take
long for
Japanese to do their damage. When the smoke
cleared, the Navy
counted
its
losses.
Eighteen
ships
had
been
sunk
or
badly
damaged.
Nearly 150 planes had been destroyed.
More than 2,400 Americans had
been
killed and more than 1,200 wounded.
24.
Great Depression in the U.S.
In 1929, the bills started to come in.
American industry had produced
too
many
goods.
Americans
could
not
afford
to
buy
all
of
them.
So
factories
had
to
cut down on
their
production.
Many
workers
lost
their
jobs. Investors tried
to get their money back. But businesses did not
have
enough
money
to
pay
them.
Banks
tried
to
get
their
money
back
from
investors. But the investors could not
pay, either. Too many people owed
money.
And
few
of
them
could
pay
their
bills.
During
the
next
few
years,
business got worse and worse. By 1932, banks all
over the country
were
closing.
People
without
money
could
not
buy
goods.
So
more
businesses closed. More and more people
lost their
jobs. By 1932, more
than
12
million
Americans
were
jobless.
Millions
more
were
earning
barely enough to live on. The country
was in a great depression they had
never experienced before.
25.
A Place of Our
Own
We
are
all
usually
very
careful
when
we
buy
something
for
the
house. Why? Because we
have to live with it for a long time. We paint a
room to make it brighter, so we choose
the colors carefully. We buy new
curtains in order to match the newly
decorated room, so they must be the
right color. We move the furniture
round so as to make more
space
—
or
we buy
new furniture
—
and so on. It
is an endless business. Rich or poor,
we
take
time
to
furnish
a
room.
Perhaps
some
people
buy
furniture
in
order
to
impress
their
friends.
But
most
of
us
just
want
to
enjoy
our