As we all know, the ocean moves. But waves breaking on
the beach make the ocean fun. When you stand on the shore and look at the
waves, it seems like the water is moving towards you. But the water is not
really moving forward. The moving you see is wave energy. And wave energy comes
from the wind.
Let’s think about how this works. As wave energy
passes through the water, the energy makes particles （粒子） of water move up and down. Just give you an example
of a wave passing under a basketball. We put a basketball on the sea. When the
wind blows, a wave comes from behind the basketball. The basketball moves up to
the top with the wave. Then the wave continues and leaves the basketball
behind. The basketball looks lower, but it doesn’t move forward. That’s because
the wave energy just moves the water which is under the basketball.
So why
can you see a wave knock you down on the shore？When a
wave moves toward the shore, the bottom of the wave slows down because it meets
the ocean floor. But the top, which is called crest(浪峰), keeps moving. The different action causes the wave
to fall over or break onto the shore. If a wave is very large, it carries a lot
of energy when it hits the land. As time goes by, waves can break up and carry
away the rocks and other things on the shore. Shorelines are changing all the
time because of wave action.
1.______ is really moving forward when you look at the
wave.
A．Water B．The
basketball C．Water and
wave energy D．Wave energy
2.Match the sentences with the pictures and the right
answer.
(1) The basketball moves up to the top with the wave.
(2) The basketball continues and leaves the basketball
behind.
(3) When the wind blows, a wave comes from behind the
basketball.
A．a—(2) b—(1) c—(3) B．a—(3) b—(1) c—(2)
C．a—(1) b—(3) c—(2) D．a—(3) b—(2) c—(1)
3.Which of the following is NOT true according to the
passage?
A．Wave energy
comes from the water.
B．Large waves
carry plenty of energy.
C．Wave action
makes shorelines change all the time.
D．The bottom of
the wave is easy to slow down.
4.The underlined word “it” ( Paragraph 3) refers to
“________”.
A．particles of
water B．the shore C．the wind D．the bottom of
the wave
5.The main idea of this passage is ______.
A．what makes
particles of water move B．how a
basketball moves on the ocean
C．how wave
energy causes wave action D．why a wave
can knock you down
