Question

read the paragraph. then, answer the questions.

types of rocks

rocks are classified as igneous, sedimentary, or metamorphic, depending on how they were formed. igneous rocks form when volcanoes erupt and release a molten rock material called magma. after magma cools, it forms solid igneous rock. one type of igneous rock is granite, a very hard material used in construction. sedimentary rocks form when water deposits sediment, or small pieces of rock and sand. over time, sediment compresses into layers. these layers form sedimentary rock, such as limestone. sedimentary rock often contains fossils and shells. metamorphic rocks are the least common rock variety. metamorphic rocks, such as marble, begin as igneous or sedimentary rocks that are squeezed tightly within earths crust over a long time.

1. what is the main idea of this paragraph?

a. hard rocks can be useful for building sturdy structures.
b. there are three types of rock that are formed in different ways.
c. not all rocks look the same.

1. what are the three types of rocks?

1. how do igneous rocks form?

1. how do sedimentary rocks form?

1. how do metamorphic rocks form?

Explanation:

Identify the main idea

The paragraph introduces rocks by stating they are classified into three types depending on how they form. It then describes each type (igneous, sedimentary, and metamorphic) and their formation processes. Therefore, the main idea is that there are three types of rock formed in different ways. We use Context Clues from the opening sentence to confirm this.

Identify the three types of rocks

The first sentence explicitly lists the three classifications: "Rocks are classified as igneous, sedimentary, or metamorphic..."

Explain igneous rock formation

According to the text, igneous rocks form when volcanoes erupt and release molten rock material called magma. After the magma cools, it forms solid igneous rock.

Explain sedimentary rock formation

The text states that sedimentary rocks form when water deposits sediment (small pieces of rock or sand). Over time, sediment compresses into layers, which form sedimentary rock.

Explain metamorphic rock formation

The text explains that metamorphic rocks begin as igneous or sedimentary rocks that are squeezed tightly within Earth's crust over a long time.

Answer:

Question 8

• (A) Hard rocks can be useful for building sturdy structures.
• (B) There are three types of rock that are formed in different ways. (Correct answer)
• (C) Not all rocks look the same.

Question 9

Igneous, sedimentary, and metamorphic.

Question 10

They form when volcanoes erupt and release magma, which then cools and solidifies.

Question 11

They form when water deposits sediment that compresses into layers over time.

Question 12

They form when igneous or sedimentary rocks are squeezed tightly within Earth's crust over a long period of time.