- 2017年12月12日15:45 来源：小站整理
- 参与（0） 阅读（1101）
The Moon, which has undergone a distinct and complex geological history, presents a striking appearance. The moon may be divided into two major terrains: the Maria (dark lowlands) and the Terrace (bright highlands). The contrast in the reflectivity (the capability of reflecting light) of these two terrains suggested to many early observers that the two terrains might have different compositions, and this supposition was confirmed by missions to the Moon such as Surveyor and Apollo. One of the most obvious differences between the terrains is the smoothness of the Maria in contrast to the roughness of the highlands. This roughness is mostly caused by the abundance of craters: the highlands are completely covered by large craters (greater than 40-50 km in diameter), while the craters of the Maria tend to be much smaller. It is now known that the vast majority of the Moon's craters were formed by the impact of solid bodies with the lunar surface.
Most of the near side of the Moon was thoroughly mapped and studied from telescopic
pictures years before the age of space exploration. Earth-based telescopes can resolve objects as small as a few hundred meters on the lunar surface. Close observation of craters, combined with the way the Moon diffusely reflects sunlight, led to the understanding that the Moon is covered by a surface layer, or regolith, that overlies the solid rock of the Moon. Telescopic images permitted the cataloging of a bewildering array of land forms. Craters were studied for clues to their origin; the large wispy marks were seen. Strange, sinuous features were observed in the Maria. Although various land forms were catalogued, the majority of astronomers' attention was fixed on craters and their origins.
Astronomers have known for a fairly long time that the shape of craters changes as they increase in size. Small craters with diameters of less than 10-15 km have relatively simple shapes.
They have rim crests that are elevated above the surrounding terrain, smooth, bowl-shaped interiors, and depths that are about one-sixth their diameters. The complexity of shape increases for larger craters.
1. What does the passage mainly discuss?
(A) What astronomers learned from the Surveyor and Apollo space missions.
(B) Characteristics of the major terrains of the Moon.
(C) The origin of the Moon's craters.
(D) Techniques used to catalogue the Moon's land forms.
2. The word "undergone" in line 1 is closest in meaning to
3.According to the passage , the Maria differ from the Terrace mainly in terms of
(B) manner of creation
4. The passage supports which of the following statements about the Surveyor and Apollo
(A) They confirmed earlier theories about the Moon's surface.
(B) They revealed that previous ideas about the Moon's craters were incorrect.
(C) They were unable to provide detailed information about the Moon's surface.
(D) They were unable to identify how the Moon's craters were made.
5. The word "vast" in line 11 is closest in meaning to
6.All of the following are true of the Maria EXCEPT:
(A) They have small craters.
(B) They have been analyzed by astronomers.
(C) They have a rough texture.
(D) They tend to be darker than the terrace.
7.All of the following terms are defined in the passage EXCEPT
(A) Moon (line 1)
(B) reflectivity (line 3)
(C) regolith (line 16)
(D) Maria (line 2)
8. 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 the Earth and the Moon
9.According to the passage , lunar researchers have focused mostly on
(A) the possibility of finding water on the Moon
(B) the lunar regolith
(C) cataloging various land formations
(D) craters and their origins
10. The passage probably continues with a discussion of
(A) the reasons craters are difficult to study
(B) the different shapes small craters can have
(C) some features of large craters
(D) some difference in the ways small and large craters were formed