The author mentions "wispy marks" in line 19 as an example of（） A: an aspect of the lunar surface discovered through lunar missions B: a characteristic of large craters C: a discovery made through the use of Earth-based telescopes D: features that astronomers observed to be common to Earth and the Moon

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

Thomas Young was the first to determine the light speed in an Earth-based experiment.

The Australian aborigines’ way of“telling time”is based on ________. A: A.the change of the sun rays B: B.the movement of the earth in relation to the sun C: C.the position of the stone D: D.the position of the tree or the cliff

News Report 3 Questions 5 to 7 are based on the news report you have just heard. A: Storm surges. B: The moon's pull. C: Large population. D: The earth's pull.

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

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