Lesson 9 Volcanoes

The surface of Earth is not a solid place. There are many holes, some of which allow magma^① to reach the earth’s surface^② from deep inside.

Magma comes from deep inside Earth where it’s hot. It’s so hot that rocks melt^③.Magma is molten, or melted rock. Because of the heat, there is also pressure. When things such as air, gases, or molten rock get hot, they expand, or get bigger. That means they need space. Weak parts of Earth’s crust^④ get pushed aside, or opened up.The magma follows the easiest path, usually along fissures, or cracks, toward the surface.

When it does reach the surface, magma is called lava. If there is a great deal of pressure behind the magma, it explodes^⑤ through the crust’s surface, sending dust, ash, lava, and rocks high into the air. When there is only a little pressure, the magma may simply bubble^⑥ up and form a lava flow that spreads across the land.

A volcano may be active, or experience eruptions, on a fairly regular basis.Or it may lie dormant^⑦, or inactive, for hundreds of years. Scientists, called volcanologist, are always ready to learn more because each volcano is unique and may teach them something new about the inner workings of Earth.

（211 words）

Notes

① magma [ 'mæɡmə] n. [地质] 岩浆；糊剂

② surface [ 'sɜːfɪs ] n. 表面；表层；外观

adj. 表面的，肤浅的

vi. 浮出水面

vt. 使浮出水面；使成平面

③ melt [ melt] vi. 熔化，溶解；渐混

vt. 使融化；使熔化；使软化；使感动

n. 熔化；熔化物

④ crust [ krʌst] n. 地壳；外壳；面包皮；坚硬外皮

vi. 结硬皮；结成外壳

vt. 盖以硬皮；在……上结硬皮

⑤ explode [ɪk'spləʊd] vi. 爆炸，爆发；激增

vt. 使爆炸；爆炸；推翻

⑥ bubble ['bʌbl] vi. 沸腾，冒泡；发出气泡声

vt. 使冒泡；滔滔不绝地说

n. 气泡，泡沫，泡状物；透明圆形罩，圆形顶

⑦ dormant [ 'dɔːmənt] adj. 休眠的；静止的；睡眠状态的；隐匿的

Exercises

Ⅰ. How well did you read?

1. [Check the details] Where does magma come from to reach the earth?

A. From deep inside Earth.

B. From the path.

C. From the surface of the earth.

2. [Evaluate the information] Volcanic eruptions are one of the most striking___events.

A. man-made 　B. natural 　C. machine-made

Ⅱ. Read for words.

1. Choose one best paraphrase or Chinese meaning for the underlined words.

（1） When things such as air, gases, or molten rock get hot, they expand, or get bigger. （Para. 2, line 3）

A. get bigger 　B. get smaller 　C. get fatter

（2） The magma follows the easiest path, usually along fissures, or cracks,toward the surface. （Para. 2, line 5）

A. holes 　B. doors 　C. cracks

（3） Scientists, called volcanologist, are always ready to learn more because each volcano is unique and may teach them something new about the inner workings of Earth. （Para. 4, line 3）

A. 独一无二的 　B. 稀罕的 　C. 特别的

2. Choose one best paraphrase or Chinese meaning for the underlined expressions.

（1） Weak parts of Earth’s crust get pushed aside, or opened up. （Para. 2, line 4）

A. rush to the other side

B. press inside

C. go away

（2） A volcano may be active, or experience eruptions, on a fairly regular basis.（Para. 4, line 1）

A. 时不时 　B. 定期 　C. 经常

Ⅲ. Writing practice.

1. What does the passage mainly talk about?

2. Read the article and find out why volcanoes erupt?

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