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Finding the Direction and Location
How can you tell which direction? By day, look for the Sun. It is in the east in the morning and the west in the afternoon. At night, use the Big Dipper to help you find the North Star. It would be better to bring a compass because its needle always points north.
How do you know how far you have gone? You could count every step. Each step is about two feet. You’d better wear a pedometer which is a tool that counts steps. If you know where you started, which direction you are heading, and how far you have gone, you can use a good map to figure out exactly where you are.
Today there is a new way for travelers to figure out where they are. It is the GPS. It has 24 satellites that orbit the earth and constantly broadcast their positions. Someday you may carry a small receiver as you hike and use GPS to find out if you are there yet!
How do you know how far you have gone? You could count every step. Each step is about two feet. You’d better wear a pedometer which is a tool that counts steps. If you know where you started, which direction you are heading, and how far you have gone, you can use a good map to figure out exactly where you are.
Today there is a new way for travelers to figure out where they are. It is the GPS. It has 24 satellites that orbit the earth and constantly broadcast their positions. Someday you may carry a small receiver as you hike and use GPS to find out if you are there yet!
Useful Words and Expressions:
1. dipper北斗七星
1. dipper北斗七星
2. compass 罗盘
3. pedometer 步数计
4. GPS= Global Position System全球定位系统
5. orbit 轨道，绕……轨道而行
6. receiver 接收器
3. pedometer 步数计
4. GPS= Global Position System全球定位系统
5. orbit 轨道，绕……轨道而行
6. receiver 接收器
Waves
How does light get from the sun to the earth? How does music get from the stage to the audience? They move the same way-----in waves!
Light and sound are fomp3s of energy. All waves carry energy, but they may carry it differently. Light and sound travel through different kinds of matter. For example, light waves cannot move through walls, but sound waves can. That is why you can hear people talking in another room even though you cannot see them. The energy of some waves is d
estructive. An earthquake produces seismic waves.
Catch a wave. Ask a friend to stand a few feet away from you. Stretch a spring between you. Shake the spring to transfer energy to it. What happens? The spring bounces up and down in waves. When the waves reach your friend, they bounce back to you!
Light waves travel 300,000 kilometers (186,000 miles) per second! They can also travel through a vacuum. That is why light from the sun and distant stars can travel through space to the earth!
Catch a wave. Ask a friend to stand a few feet away from you. Stretch a spring between you. Shake the spring to transfer energy to it. What happens? The spring bounces up and down in waves. When the waves reach your friend, they bounce back to you!
Light waves travel 300,000 kilometers (186,000 miles) per second! They can also travel through a vacuum. That is why light from the sun and distant stars can travel through space to the earth!
Useful Words and Expressions;
1. destructive 破坏的
2. seismic地震的
3. vacuum真空
1. destructive 破坏的
2. seismic地震的
3. vacuum真空
Flowering Plants
What are the parts of a flower?
Flowers can have male parts and female parts. The female parts make eggs that become seeds. The male parts make pollen. Pollen is a powdery material that is needed by the eggs to make seeds. To make seeds, pollen and eggs must come together. The wind, insects, and birds bring pollen to eggs. Many animals love flowers’ bright colors. They also like a sugary liquid in flowers. This is called nectar. While they drink nectar, pollen rubs off on their bodies. As they move, some of this pollen gets delivered to the female flower parts.
Over time, the female parts turn into fruits that contain seeds. Animals often eat the fruits and the seeds pass through their bodies as waste. The animals do no know they are working for the plants by planting seeds as they travel to different places!
Useful words and Expressions:
1. flowering 开花的
2. pollen 花粉
3. powdery 粉状的
4. sugar 含糖的，甜的
6. rub 磨擦
Living Things React
as long as you love me mp3You and all organisms live an environment. An environment is made up of everything that surrounds an organism. It can include the air, the water, the soil, and even other organisms.
An organism responds to changes in its environment. When an organism responds to a change, it reacts in certain ways. All living things respond in some way.
Have you ever noticed how plants and insects respond to light? Plants bend toward light. Insects fly toward light.
Living things also respond in other ways. The leaves on some trees respond to a change in
season. In autumn, they change colors and then fall off the branches Animals also respond to a change in season. Squirrels save nuts for the winter. Bears sleep through the winter in a cave.
You respond to your environment in many ways, too. You may shiver if you are cold. What other ways do you respond to changes in your environment?
A Guide's Answer
In 1861, the Civil War started in the United States between the Northern and the Southern states. The war continued with great bitterness until 1865, when the Northerners were victorious. However, even today, many Southerners have not forgotten their defeat, or forgiven the Northerners.
A few years ago, a party of American tourists were going round one of the battlefields of the Civil War with a guide who came from one of the Southern states. At each place, the guide told the tourists stirring stories about how a few Southern soldiers had conquered powerful forces of Northerners there.
At last, one of the tourists, a lady who came from the North, stopped the guide and said to him, “ But surely that the Northern amp3y must have won at least one victory in the Civil War?”
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