Meaning: 'Creatures' refers to living beings, especially animals, emphasizing the biological aspect of arthropods.

Wrong options:

• mice: Mice are a specific type of animal and do not encompass the broader category of arthropods, making it contextually incorrect.
• bones: Bones are inanimate structures and do not relate to the living nature of arthropods, thus failing to fit the context.
• structures: Structures imply physical forms or frameworks, which does not accurately describe the living organisms being discussed.

Correct answer: depend

Explanation: The verb 'depend' is correctly used here to indicate reliance, fitting the grammatical structure of the sentence. It aligns with the context of ecosystems and the relationship between humans and arthropods.

Meaning: 'Depend' means to rely on or need something for support or existence, highlighting the importance of arthropods in ecosystems.

Wrong options:

• survive: While 'survive' relates to living, it does not convey the idea of reliance as effectively as 'depend' does in this context.
• live: 'Live' refers to existence but does not capture the relationship of reliance that 'depend' conveys.
• decide: 'Decide' implies making a choice, which is unrelated to the context of reliance on ecosystems.

Correct answer: make

Explanation: The verb 'make' is appropriate here as it indicates composition or formation, fitting grammatically and contextually with the subject of arthropods and their contribution to animal species.

Meaning: 'Make' in this context means to constitute or form, indicating that arthropods are a significant part of the total animal species.

Wrong options:

• compose: While 'compose' is similar, it is often used in a more formal context and does not fit as naturally in this sentence structure as 'make'.
• pull: 'Pull' does not relate to the context of composition and is grammatically incorrect in this usage.
• include: 'Include' suggests a part of a whole but does not convey the same sense of contribution as 'make' does.

Correct answer: thanks to

Explanation: The phrase 'thanks to' is correctly used to indicate a positive outcome resulting from the collaboration, fitting both grammatically and contextually within the sentence.

Meaning: 'Thanks to' means due to or as a result of, highlighting the beneficial role of community scientists in the study.

Wrong options:

• while: 'While' suggests a contrast or simultaneous action, which does not fit the context of attributing success to the collaboration.
• because: 'Because' introduces a reason but does not convey the same positive acknowledgment as 'thanks to'.
• contrary to: 'Contrary to' implies opposition, which is not relevant in this context where collaboration is being praised.

Correct answer: collect

Explanation: The verb 'collect' is appropriate as it indicates the action of gathering specimens, fitting grammatically and contextually with the role of community scientists in the study.

Meaning: 'Collect' means to gather or accumulate items, in this case, specimens from various locations for research purposes.

Wrong options:

• unfold: 'Unfold' implies revealing or developing, which does not accurately describe the action of gathering specimens.
• substitute: 'Substitute' means to replace something, which is unrelated to the action of gathering specimens.
• pressure: 'Pressure' refers to force or stress, which does not fit the context of collecting specimens.