Meaning: 'Preserve' means to maintain something in its original or existing state, in this case, the oceans' beauty and resources.

Wrong options:

• underscore: The verb 'underscore' means to emphasize or highlight, which does not fit the context of maintaining the oceans' state.
• mitigate: The verb 'mitigate' means to make something less severe, which does not directly relate to the act of preserving the oceans.
• need: The noun 'need' refers to a requirement or necessity, which does not fit grammatically as it does not serve as a verb in this context.
• plastic: The noun 'plastic' refers to a synthetic material, which does not fit as it does not convey the action of maintaining the oceans.
• implement: The verb 'implement' means to put something into effect, which does not fit the context of preserving the oceans' state.

Correct answer: plastic

Explanation: The noun 'plastic' fits grammatically as it serves as the object of the preposition 'reducing.' Contextually, it aligns with the discussion of pollution that threatens marine life, making it a suitable choice.

Meaning: 'Plastic' refers to a synthetic material that is often non-biodegradable and contributes to pollution in oceans.

Wrong options:

• underscore: The verb 'underscore' does not fit as it is not a noun and does not relate to types of pollution.
• mitigate: The verb 'mitigate' does not fit as it is not a noun and does not refer to a type of pollution.
• need: The noun 'need' does not fit as it does not refer to a type of pollution and is not relevant in this context.
• preserve: The verb 'preserve' does not fit as it does not refer to a type of pollution and is not a noun.
• implement: The verb 'implement' does not fit as it is not a noun and does not relate to types of pollution.

Correct answer: implement

Explanation: The verb 'implement' fits grammatically as it is in the base form, which is appropriate following 'can.' Contextually, it aligns with the idea of putting strategies into action for marine conservation, making it a logical choice.

Meaning: 'Implement' means to put a plan or decision into effect, in this case, strategies for marine conservation.

Wrong options:

• underscore: The verb 'underscore' means to emphasize or highlight, which does not fit the context of executing strategies.
• mitigate: The verb 'mitigate' means to make something less severe, which does not fit the context of executing strategies for conservation.
• need: The noun 'need' does not fit grammatically as it does not serve as a verb in this context.
• plastic: The noun 'plastic' does not fit as it does not convey the action of executing strategies.
• preserve: The verb 'preserve' does not fit as it does not relate to the action of implementing strategies.

Correct answer: need

Explanation: The noun 'need' fits grammatically as it serves as the subject of the sentence. Contextually, it aligns with the urgency of taking action for marine conservation, making it a suitable choice.

Meaning: 'Need' refers to a requirement or necessity, in this case, the urgent requirement for action regarding marine conservation.

Wrong options:

• underscore: The verb 'underscore' does not fit as it is not a noun and does not serve as a subject in this context.
• mitigate: The verb 'mitigate' does not fit as it is not a noun and does not relate to the urgency of action.
• plastic: The noun 'plastic' does not fit as it does not convey the urgency of action needed for conservation.
• implement: The verb 'implement' does not fit as it is not a noun and does not serve as a subject in this context.