学进去

The human body is an amazing machine. It has many parts that form systems. The systems work together to keep you alive and healthy. Let’s look at some of your body’s systems.

There are 206 bones in your body that make up your skeleton. Your bones give your body shape and strength. They also protect your inner organs (内部器官). Most of the bones in your body are linked together at joints (关节). There are different kinds of joints. Different joints let body parts move in different ways. The joint that joins your arm and shoulder lets your arm rotate (转动). The joints at your elbows and knees let your lower arms and legs move up and down. If it were not for moving joints, you could not walk, run and swim.

Muscles control the movement of your body. There are three kinds of muscles. Skeletal muscle (骨骼肌) is the muscle that is attached to bones. It makes your arms, legs, fingers, eyes and other body parts move. Cardiac muscle is the strong heart muscle. It works around the clock. Smooth muscle is found in your skin, stomach and other organs.

Your brain and thousands of miles of nerve fibers form your body’s communication system. The brain is the control center. It receives information from your sense organs—eyes, nose, ears, tongue and skin. The brain tells muscles what to do. If your fingers go near something hot, a signal goes to the brain. It then sends a signal to tell your hand to move away.

Many other parts also help you say strong and healthy. You can help your body do its job by eating well and getting exercise. You can also help by avoiding stress and unsafe situations.

1．What is this article mainly about?

A．How your brain works.

B．How to keep your body systems healthy.

C．How to help yourself avoiding stress.

D．How systems in your body keep you alive and healthy.

2．What would happen if your bones weren’t connected by joints?

A．You would fall down.

B．You would not be able to breathe.

C．You would not be able to walk and run.

D．All of the above.

3．How can you keep yourself stay strong and healthy?

A．By eating well.	B．By doing exercise.
C．By avoiding stress and unsafe.	D．All of the above.

4．Which of these statements is true?

A．You are able to run and swim without moving joints.

B．All the bones in your body are linked together at joints.

C．The brain is the control center.

D．Smooth muscle is found in your skeleton.

5．Which is the best title of this passage?

A．Inside your body	B．Our muscles
C．Keep you alive and healthy	D．Joints is important

6．How many body systems are mentioned in this passage? Which body system do you think is the most important? Why?
________________________________________________________________