Meaning: 'Revealed' means to make something known or visible that was previously hidden.

Wrong options:

• spotted: 'Spotted' is the past tense of 'spot,' which does not fit here as it does not convey the action of showing or uncovering.
• concealed: 'Concealed' is the past participle of 'conceal,' meaning to hide something, which is the opposite of what is intended in this context.
• accumulated: 'Accumulated' refers to gathering or collecting over time, which does not fit the context of showing or revealing.
• proves: 'Proves' is the present tense of 'prove,' which does not match the past tense structure required here and does not convey the action of revealing.

Correct answer: lurking

Explanation: The word 'lurking' is the present participle of the verb 'lurk,' which fits grammatically as it describes the ongoing action of the creatures being hidden or waiting in a concealed manner. The context suggests that these creatures are present but not immediately visible, which aligns with the meaning of 'lurking.'

Meaning: 'Lurking' means to remain hidden or concealed, often with a sense of waiting or ambushing.

Wrong options:

• spotted: 'Spotted' is the past tense of 'spot,' which does not fit here as it implies visibility rather than concealment.
• concealed: 'Concealed' is the past participle of 'conceal,' meaning to hide something, which does not fit the context of creatures being present.
• accumulated: 'Accumulated' refers to gathering or collecting, which does not convey the idea of being hidden or waiting.
• proves: 'Proves' is the present tense of 'prove,' which does not fit the context of describing the state of the creatures.

Correct answer: spotted

Explanation: The word 'spotted' is the past tense of the verb 'spot,' which fits grammatically as it describes the action taken by marine biologists in the past. The context indicates that they have seen or identified these species, which aligns with the meaning of 'spotted.'

Meaning: 'Spotted' means to see or notice something, especially something that is not immediately obvious.

Wrong options:

• concealed: 'Concealed' is the past participle of 'conceal,' meaning to hide something, which does not fit the context of identifying species.
• accumulated: 'Accumulated' refers to gathering or collecting over time, which does not fit the context of seeing or identifying species.
• proves: 'Proves' is the present tense of 'prove,' which does not match the past tense structure required here and does not convey the action of spotting.
• revealed: 'Revealed' is the past participle of 'reveal,' which does not fit here as it does not describe the action of identifying species.

Correct answer: underscores

Explanation: The word 'underscores' is the present tense of the verb 'underscore,' which fits grammatically as it indicates an ongoing action that emphasizes the wealth of life. The context suggests that the findings highlight or stress the abundance of life in extreme environments, which aligns with the meaning of 'underscores.'

Meaning: 'Underscores' means to emphasize or highlight something, making it more noticeable or significant.

Wrong options:

• spotted: 'Spotted' is the past tense of 'spot,' which does not fit here as it does not convey the action of emphasizing or highlighting.
• concealed: 'Concealed' is the past participle of 'conceal,' meaning to hide something, which does not fit the context of emphasizing life.
• accumulated: 'Accumulated' refers to gathering or collecting, which does not convey the idea of emphasizing or highlighting.
• proves: 'Proves' is the present tense of 'prove,' which does not fit the context of emphasizing the wealth of life.