Question

igneous rocks
igneous rocks form when molten material cools and solidifies, either inside or on the surface of the earth. when this melted rock is below the earth’s surface, it’s called magma. when magma rises to the surface through cracks or volcanic eruptions, it’s called lava. when lava cools and hardens on the earth’s surface, it becomes igneous rock. since lava cools quickly, it forms very small crystals, which makes the rock look dull and less sparkly. however, if magma cools slowly underground over thousands of years, it forms larger crystals. these larger crystals result in a type of igneous rock known as plutonic rock, which has a coarse texture and can be quite sparkly.

1. the author’s main purpose for writing the article is to -

ⓐ tell how an igneous rock forms
ⓑ share all the types of igneous rocks
ⓒ provide an example of igneous rocks
ⓓ show how a crystal is formed

1. the author organizes the article by -

ⓐ comparing
ⓑ explaining
ⓒ describing
ⓓ listing

Explanation:

For question 8: The article focuses on explaining the formation process of igneous rocks, including how magma/lava cools to form them, rather than just listing types, giving a single example, or explaining crystal formation alone.
For question 9: The author structures the text by breaking down and explaining the origin, cooling processes, and resulting characteristics of igneous rocks step by step, not primarily comparing, just describing without explanatory structure, or listing items.

Answer:

1. A. tell how an igneous rock forms
2. B. explaining