The ISS is as tall as a nine-story building and weighs 186，900 kilograms.It's about the size of two football fields and flies about 400 kilometers above our heads at 28，970 kilometers per hour.It goes around Earth once every 90 minutes.
   If you watch the sky for about an hour after the sun goes down，you may see some "moving stars".But they are not really stars.They are man-made satellites.And the biggest of all is the International Space Station （ISS）.From May to July is the best season to watch the ISS flying over the earth.And people can see it with their eyes during the time.
   The scientists want to live on the ISS.They think that the best way to learn more about space is to live there.
   When the space station is finished，it will be like a city in space.People will stay and study there with many of the thing they have at home.Laboratories，living rooms and power stations are being built.The ISS is the most ambitious（雄心勃勃的） and expensive program.Billions of dollars are spent on it every year.
   Scientists hope that the ISS will be a stepping stone（跳板） for future space exploration. "The ISS will be more useful some day.The ISS will help us understand the human body better，explore space and study the earth.It can help us make life on the earth better." said Kathryn Clark，an ISS scientist.
   Sixteen countries are part of the space program：the US，Russia，Canada，Japan，Brazil，and 11 European countries.
   China isn't an ISS country，but it has helped with some of the experiments.In 2003，China sent some rice up to the ISS to find out what space would do to it.
   After it's finished，more than 90 percent of the world's population is able to see the Space Station.So keep looking up，and maybe you'll see it getting bigger.

（1）What does ISS represent？

It represents International Space Station.

It represents International Space Station.

（2）How fast does ISS fly？

It flies at 28，970 kilometers per hour.

It flies at 28，970 kilometers per hour.

（3）Give 2 examples of the items that are being built on the ISS.

Laboratories

Laboratories

，

living rooms

living rooms

.
（4）China is not an ISS country，is it？

No

No

，

it isn't

it isn't

.
（5）Why do scientists build ISS？

Because they hope that the ISS will be a stepping stone（跳板） for future space exploration.

Because they hope that the ISS will be a stepping stone（跳板） for future space exploration.

（6）What advantage do you take over the project of ISS？

We can see the Space Station.

We can see the Space Station.