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 40-50km 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, which 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 circular maria were mapped. Wispy marks on the surface (known as rays) emanating from certain craters 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 10-15km 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-fifth to one-sixth their diameters. The complexity of shape increases for larger craters.
1. What does the passage mainly discuss?
2. The underlined 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（ ）.
4. According to the passage lunar researchers have focused mostly on（ ）.
5. The passage probably continues with a discussion of（ ）.
问题1选项
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.
问题2选项
A.altered
B.substituted
C.experienced
D.preserved
问题3选项
A.age
B.manner of creation
C.size
D.composition
问题4选项
A.the possibility of finding water on the Moon
B.the lunar regolith
C.cataloging various land formations
D.craters and their origins
问题5选项
A.the reasons craters are difficult to study
B.the different shapes
C.some features of large craters
D.some difference in the ways small and large craters were formed
第1题:B
第2题:C
第3题:D
第4题:D
第5题:C
第1题:
主旨大意题。A选项“天文学家从勘测者号和阿波罗号太空任务中学到了什么”；B选项“月球主要地形的特征”；C选项“月球陨石坑的起源”：D选项“用来记录月球地貌的技术”。根据题干定位到第一段第一句话The Moon, which has undergone a distinct and complex geological history, presents a striking appearance.（月球经历了独特而复杂的地质历史，呈现出惊人的外观。）第二段倒数第一二句话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.（在月海中观察到奇怪的、弯曲的特征。虽然有各种各样的地貌，但天文学家的注意力主要集中在陨石坑和它们的起源上。）从这里可以看出文章都是围绕着月球的地形地貌展开的，所以答案选B；C选项只是提及没有具体展开讲，而且文章不止讲了月球上的陨石坑还有相当一部分内容是讲的月海（maria），所以不能选，A、D选项不符合题意。
第2题:
词义推测题。A选项“改变”；B选项“取代”；C选项“经历”；D选项“保存”。第一段第一句话The Moon, which has undergone a distinct and complex geological history, presents a striking appearance.（月球经历了独特而复杂的地质历史，呈现出惊人的外观）。从这句undergone的意思是经历，这个和选项C相近，所以答案选C。
第3题:
词义推测题。A选项“年龄”；B选项“创造的方式”；C选项“尺寸”；D选项“成分”。第一段第三四五句话…observers that the two terrains might have different compositions…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（……观察者认为这两种地形可能有不同的组成……这两种地形最明显的区别之一就是平坦的海地与粗糙的高地形成对比。这种粗糙度主要是由大量的陨石坑造成的；高地完全被大型火山口所覆盖），从这里可知因为组成成分不同所以造成了两者的不同，而两者的不同主要是粗糙程度，粗糙程度是因为陨石坑多的地方就很粗糙，而月海没有陨石坑，所以不那么粗糙，归根结底主要还是构成的地形不一样，所以答案选D。
第4题:
细节理解题。题干：根据文章，月球研究人员主要关注的是……A选项“在月球上找到水的可能性”；B选项“月球表面风化层”；C选项“各种地形分类”；D选项“陨石坑和它们的起源”。根据题干定位到第二段最后一句话Although various land forms were catalogued, the majority of astronomers’ attention was fixed on craters and their origins.（虽然有各种各样的地貌，但天文学家的注意力主要集中在陨石坑和它们的起源上），由此可知科学家的重点是在陨石坑及其起源，所以答案选D；其他选项文章没有提及。
第5题:
判断推理题。题干：这篇文章可能会继续讨论。A选项“陨石坑形成的原因很难研究”，B选项“不同的形状”，C选项“一些大型陨石坑的特征”；D选项“大小陨石坑形成的方式有些不同”。定位到文章最后一段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 10-15km 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-fifth to one-sixth their diameters. The complexity of shape increases for larger craters.（天文学家很早就知道，陨石坑的形状会随着体积的增大而改变。直径小于10-15公里的小陨石坑形状相对简单。它们的边缘嵴高于周围的地形，光滑的碗状内部，深度约为直径的五分之一到六分之一。陨石坑越大，其形状的复杂性就越大），文章最后一段描写了小陨石坑的一些特征，然后最后一句话说的是陨石坑越大，形状越复杂，所以从这里可以推断接下来文章会要讲大陨石坑的结构和特征了，因此答案选C。
