托福阅读真题练习：岩石的文本+真题+答案

2017年11月06日15:42 来源：小站整理: 参与（0）阅读（23983）

摘要：托福阅读真题哪里有?大家平时备考托福阅读考试的时候都用的是哪些真题呢?除了官方真题Official的托福阅读真题以外，大家进行托福阅读的练习大多数可能都是根据老托资料或者是课外资料来练习了。那么到哪里去找到托福阅读真题来进行练习呢?

托福阅读如何进行备考?除了大量的托福词汇储备以外，大家可能最需要的就是托福阅读真题的练习。那么除了官方真题Official你还有哪些托福阅读真题进行练习呢?今天小编就为大家整理了托福阅读真题100篇：岩石的文本、题目以及答案，希望可以帮助到大家。

托福阅读100篇真题练习汇总：http://toefl.zhan.com/tfziliao63739.html

托福阅读文本：

Any rock that has cooled and solidified from a molten state is an igneous rock. Therefore, if the Earth began as a superheated sphere in space, all the rocks making up its crust may well have been igneous and thus the ancestors of all other rocks. Even today, approximately 95 percent of the entire crust is igneous. Periodically, molten material wells out of the Earth's interior to invade the surface layers or to flow onto the surface itself. This material cools into a wide variety of igneous rocks. In the molten state, it is called magma as it pushes into the crust and lava when it runs out onto the surface.

All magma consists basically of a variety of silicate minerals (high in silicon-oxygen compounds), but the chemical composition of any given flow may differ radically from that of any other. The resulting igneous rocks will reflect these differences. Igneous rocks also vary in texture as well as chemistry. Granite, for instance, is a coarse-grained igneous rock whose individual mineral crystals have formed to a size easily seen by the naked eye. A slow rate of cooling has allowed the crystals to reach this size. Normally, slow cooling occurs when the crust is invaded by magma that remains buried well below the surface. Granite may be found on the surface of the contemporary landscape, but from its coarse texture we know that it must have formed through slow cooling at a great depth and later been laid bare by erosion. Igneous rocks with this coarse-grained texture that formed at depth are called plutonic.

On the other hand, if the same magma flows onto the surface and is quickly cooled by the atmosphere, the resulting rock will be fine-grained and appear quite different from granite, although the chemical composition will be identical. This kind of rock is called rhyolite. The most finely grained igneous rock is volcanic glass or obsidian, which has no crystals. Some researchers believe this is because of rapid cooling; others believe it is because of a lack of water vapor and other gases in the lava. The black obsidian cliffs of Yellowstone National Park are the result of a lava flow of basalt running head on into a glacier. Some of the glacier melted on contact, but suddenly there also appeared a huge black mass of glassy stone.

托福阅读题目：

1. In the first paragraph, the author mentions that 95% of the Earth's crust is composed of igneous rock to support the idea that

(A) the Earth began as a molten mass

(B) a thin layer of magma flows beneath the Earth's crust

(D) igneous rock is continually being formed

2. The word "invade" in line 5 is closest in meaning to

(A) move into

(B) neutralize

(D) deposit

3. The word "contemporary" in line 15 is closest in meaning to

(A) vast

(B) natural