（ ）is the first of many Earth-orbiting satellites designed for observation of the Earth’s land areas. A: Landsat 1 B: IKONOS C: SPOT D: QUICKBIRD

34. Cospas-Sarsat comprises a several near polar orbiting satellites and一． A: a network of land based earth stations B: several coast stations C: an earth station D: some RCCs

Russian space __________ is currently orbiting the Earth.

No force of gravity acts on an astronaut in an orbiting space station.

_____ is covered with heavy snow. A: The earth’s surface B: The surface of earth C: The surface earth D: The earth surface

The GPS receiver is able to receive signals that are transmitted by stars orbiting overhead.

The earth _______ round the sun, and the moon _________ round the earth

______ is the center of our planetary system was a difficult concept to grasp in the Middle Ages.(1.0) A: It is the sun and not the earth B: Being the sun and not the earth C: The sun and not the earth D: That the sun and not the earth

The purpose of Earth Day is ______. A: to help people memorize the earth B: to help people to learn how to protect the earth C: to unite all the people on the earth D: all of the above

One day on the moon is ______. A: two Earth week long B: two Earth weeks long C: two Earth weeks longer D: two Earth weeks length