首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Rocks which have solidified directly from molten materials are called igneous rocks. Igneous rocks are commonly referred to as p
Rocks which have solidified directly from molten materials are called igneous rocks. Igneous rocks are commonly referred to as p
admin
2011-04-26
61
问题
Rocks which have solidified directly from molten materials are called igneous rocks. Igneous rocks are commonly referred to as primary rocks because they are the original source of material found in sedimentaries and metamorphics. Igneous rocks compose the greater part of the earth’s crust, but they are generally covered at the surface by a relatively thin layer of sedimentary or metamorphic rocks. Igneous rocks are distinguished by the following characteristics: (1) they contain no fossils; (2) they have no regular arrangement of layers; and (3) they are nearly always made up of crystals.
Sedimentary rocks are composed largely of minute fragments derived from the disintegration of existing rocks and in some instances from the remains of animals. As sediments are transported, individual fragments are assorted according to size. Distinct layers of such sediments as gravels, sand, and clay build up, as they are deposited by water and occasionally wind. These sediments vary in size with the material and the power of the eroding agent. Sedimentary materials are laid clown in layers called strata.
When sediments harden into sedimentary rocks, the names applied to them change to indicate the change in physical state. Thus, small stones and gravel cemented together are known as conglomerates; cemented sand becomes sandstone; and hardened clay becomes shale. In addition to these, other sedimentary rocks such as limestone frequently result from the deposition of dissolved material. The ingredient parts are normally precipitated by organic substances, such as shells of clams or hard skeletons of other marine life.
Both igneous and sedimentary rocks may be changed by pressure, heat, solution, or cementing action. When individual grains from existing rocks tend to deform and interlock, they are called metamorphic rocks. For example, granite, an igneous rock, may be metamorphosed into a gneiss or a schist. Limestone, a sedimentary rock, when subjected to heat and pressure may become marble, a metamorphic rock. Shale under pressure becomes slate.
The person most interested in the ideas found in this passage would most likely be a ______.
选项
A、sculptor
B、archeologist
C、paleontologist
D、geologist
答案
D
解析
对本文表达的观点最感兴趣的人很可能是地质学家。sculptor(雕刻家)、archeologist(考古学家)和paleontologist(古生物学家)也许对岩石有一定的兴趣、但他们对岩石的兴趣总不会超过地质学家吧。
转载请注明原文地址:https://kaotiyun.com/show/f66O777K
0
考博英语
相关试题推荐
ReadthefollowingreviewsofabookcalledTheBossesSpeak.Foreachquestion23-28,choosethecorrectanswer.Markl
ReadthefollowingreviewsofabookcalledTheBossesSpeak.Foreachquestion23-28,choosethecorrectanswer.Markl
ReadthefollowingreviewsofabookcalledTheBossesSpeak.Foreachquestion23-28,choosethecorrectanswer.Markletter
ReadthefollowingreviewsofabookcalledTheBossesSpeak.Foreachquestion23-28,choosethecorrectanswer.Markletter
•ReadthefollowingreviewofabookcalledTheBossesSpeak.•Foreachquestion(23-28),choosethecorrectanswer.•Marko
•ReadthefollowingreviewofabookcalledTheBossesSpeak.•Foreachquestion(23-28),choosethecorrectanswer.•Marko
•ReadthefollowingreviewofabookcalledTheBossesSpeak.•Foreachquestion(23-28),choosethecorrectanswer.•Marko
随机试题
A、血管收缩B、血管舒张C、促进肾对水的重吸收D、促进肾对Na+和水的重吸收E、肾素的释放血管紧张素Ⅱ的主要作用是
肺泡囊
下列关于恒牙外伤临床检查描述错误的是
患者女性,26岁,心悸,气短,下肢水肿三年,查体:心界向两侧扩大,心尖部有舒张期的隆隆样杂音,胸骨左缘第3肋间有叹气样舒张期杂音,传至心尖,肺动脉瓣区第二心音亢进、分裂,主动脉瓣区第二心音减弱,血压18.6/7.98kPa,应诊断为
依据《安全生产法》的规定,事故调查处理应当按照()的原则,查清事故原因,查明事故性质和责任。
根据赫兹伯格的双因素理论,激励因素的缺失会导致员工()。
(2010年真题)下列关于行政责任的表述,能够成立的有
庄严国土
求下列幂级数的收敛域及其和函数:
设二次型f(x1,x2,x3)=的秩为2.求a;
最新回复
(
0
)