Running
Running is good for people with too much fat because it can help them become slim(苗条). It also makes people strong. But it may be bad for joints (关节). If we don’t feel comfortable in our joints, we should stop for another activity.
Walking
Walking makes our bodies relaxed (放松的). It can also help people to be slim.
Swimming
Swimming is a great way to make different places of your body strong. But it is not a good way to keep slim. The water in a swimming pool is cooler than our body. The body protects  itself from the cold by keeping fat.
Cycling
Riding a bike will help us be slim and make our legs strong, too. But be careful! If you live in the city, you should ride on the bike road and be away from the busy traffic to keep safe.
If you’re not well in the joints(关节) while running, you should               .

A．run faster	B．keep running
C．stop running	D．drink water

Cycling can help                 .

A．make your legs strong	B．know the way well
C．keep fat	D．walk fast

While cycling in cities, you should be away from the traffic to                 .

A．keep quiet	B．keep safe
C．ride faster	D．enjoy fresh air

You can be slim if you play these sports except (除了)               .

A．running	B．walking
C．swimming	D．cycling

What does the passage tell us about?

A．Four outdoor activities.	B．Four ways of travelling.
C．Why we need sports.	D．Four good things of sports.