Space stations are like houses in space for astronauts.They stay in space or in the Earth's orbit （軌道） （A）______a long time.In space，there is much less gravity than on Earth.The astronauts float about and must tie themselves to something before they（B）go to bed.
    Dirt （塵埃） also floats about （C）______can get inside the equipment （設(shè)備）and damage the space station，so the astronauts （D） have to be very clean，and have to put their rubbish in special bags. （E） There isn't any air in space，so the astronauts must wear special suits when they leave the space station.Astronauts cannot spend too long in space，（F）因?yàn)檫@對(duì)他們的健康有害.They must also do special exercises to stay fit （健康的）.However，one Russian astronaut stayed on a space station for 437 days!
    Perhaps in the future，people will stay for even longer on space stations.

（1）在文中（A）和（C）的空白處填入適當(dāng)?shù)膯卧~：

for

for

；

which

which

（2）寫出文中畫線部分（B）和（D）的同義詞或近義詞：

sleep

sleep

；

must

must

（3）將文中畫線部分（E）改寫為：There

is no

is no

air in space.
（4）將文中畫線部分（F）譯成英語：

Because it's bad for their health.

Because it's bad for their health.

（5）從文中找出空間站所處的兩個(gè)位置：

space

space

；

Earth's orbit

Earth's orbit