Maybe you know a lot about the city you live in.You may even

Maybe you know a lot about the city you live in.You may even know some interesting facts about Earth,but _1_ do you know about Mars?Will there be _2_ there just like people on Earth?
Mars is the fourth planet from the sun and it's the most like Earth,but it's much _3_ than Earth because it's farther from the sun.It's also the only planet whose surface can be _4_ from Earth.
Mars is often called "the red planet" because the rocks on it have a dark _5_ color.There are strong winds on Mars that can _6_ dust into the hills.For many years,people have _7_ Mars.They have sent instruments and robots there.Some of the robots got there,_8_ most failed.NASA(美国国家宇航局) sent
two robots to Mars two years ago.They wanted _9_ signs of water and life on Mars.Some day,humans will
travel to Mars and have an even _10_ look at our red neighbor.Maybe it could be you!
( )1.A.when B.what C.which D.how
( )2.A.sound B.life C.air D.water
( )3.A.hotter B.colder C.bigger D.smaller
( )4.A.seen B.wrote C.heard D.visited
( )5.A.red B.black C.white D.yellow
( )6.A.blow B.look C.mix D.fly
( )7.A.lived on B.landed on C.studied D.written
( )8.A.but B.and C.however D.or
( )9.A.leave B.use C.find D.give
( )10.A.faster B.farther C.closer D.lower

1.B.what
2.B.life
3.B.colder
4.A.seen
5.A.red
6.A.blow
7.C.studied
8.C.however
9.C.find
10.C.close