The rocks which are formed from magma are called …………… rocks.

1. sedimentary
2. igneous
3. metamorphic
4. metallic

Quartzite is …………… rock.

1. an igneous
2. a sedimentary
3. a volcanic
4. a metamorphic

Carbonic acid disintegrates limestone as a result of

1. frost action
2. oxidation
3. hydration
4. carbonation

Which of these factors is not responsible for soil formation?

1. climate
2. human activities
3. deforestation
4. parent rock material