Meaning: 'Occurs' means to happen or take place.

Wrong options:

• excludes: The verb 'excludes' implies that something is left out, which does not fit the context of describing a process that happens.
• deprivation: 'Deprivation' is a noun that refers to the state of lacking something, which does not fit grammatically or contextually in this sentence.
• results: While 'results' is a verb, it does not fit here as it suggests an outcome rather than the process of weathering itself.
• comparing: 'Comparing' is a gerund that does not relate to the action of weathering and does not fit grammatically.
• contributing: 'Contributing' is a gerund that implies adding to something, which does not fit the context of stating what happens to rocks.

Correct answer: composition

Explanation: The noun 'composition' refers to the makeup or structure of the rock, which is relevant in the context of physical weathering that does not alter it. This fits grammatically as it serves as the object of the preposition 'of.'

Meaning: 'Composition' refers to the way in which something is made up or the components that make it.

Wrong options:

• occurs: 'Occurs' is a verb that does not fit as it does not serve as a noun in this context.
• excludes: 'Excludes' is a verb that implies something is left out, which does not relate to the makeup of the rock.
• deprivation: 'Deprivation' is a noun that refers to the lack of something, which does not fit the context of discussing the makeup of rocks.
• results: 'Results' is a verb that indicates an outcome, which does not fit as it does not describe the makeup of the rock.
• comparing: 'Comparing' is a gerund that does not relate to the composition of the rock and does not fit grammatically.
• contributing: 'Contributing' is a gerund that implies adding to something, which does not fit the context of describing the makeup of the rock.

Correct answer: results

Explanation: The verb 'results' fits grammatically in the present tense and contextually indicates that chemical weathering is an outcome of chemical changes in the rock. It aligns with the structure of the sentence, which describes a cause-and-effect relationship.

Meaning: 'Results' means to occur as a consequence or outcome of something.

Wrong options:

• occurs: 'Occurs' is a verb that indicates something happening, but it does not fit the context of describing an outcome of chemical change.
• excludes: 'Excludes' implies leaving something out, which does not fit the context of describing a process that happens due to chemical change.
• deprivation: 'Deprivation' is a noun that does not fit grammatically or contextually in this sentence.
• comparing: 'Comparing' is a gerund that does not relate to the outcome of chemical weathering and does not fit grammatically.
• contributing: 'Contributing' is a gerund that implies adding to something, which does not fit the context of describing the result of chemical change.

Correct answer: contributing

Explanation: The gerund 'contributing' fits grammatically as it describes the action of plant growth in relation to chemical weathering. It indicates that plant growth plays a role in the process, aligning with the context of the sentence.

Meaning: 'Contributing' means to add to or play a part in something.

Wrong options:

• occurs: 'Occurs' is a verb that does not fit as it does not describe the action of plant growth in relation to weathering.
• excludes: 'Excludes' implies leaving something out, which does not fit the context of discussing the role of plant growth.
• deprivation: 'Deprivation' is a noun that does not fit grammatically or contextually in this sentence.
• results: 'Results' is a verb that indicates an outcome, which does not fit the context of describing the role of plant growth.
• comparing: 'Comparing' is a gerund that does not relate to the action of plant growth and does not fit grammatically.