Meaning: 'Was' indicates that something existed or occurred in the past, specifically referring to the commissioning of the installation.

Wrong options:

• the: 'The' is a definite article and does not function as a verb, making it grammatically incorrect in this context.
• when: 'When' is an adverb that introduces a time clause, which does not fit the structure of the sentence as it lacks a verb form.
• were: 'Were' is the past tense form of 'to be' used for plural subjects, which does not agree with the singular subject 'installation'.

Correct answer: already

Explanation: The word 'already' is an adverb that indicates something has happened before the present time, fitting contextually as it emphasizes the ongoing nature of the consequences of marine pollution. It aligns with the present continuous tense 'is having.'

Meaning: 'Already' means that something has occurred sooner than expected or before a certain time, highlighting the urgency of the issue.

Wrong options:

• ready: 'Ready' is an adjective meaning prepared, which does not fit the context of describing an ongoing situation.
• steady: 'Steady' is an adjective that describes something stable or constant, which does not convey the sense of urgency needed here.
• eveready: 'Eveready' is not a standard English word in this context and does not fit grammatically or contextually.

Correct answer: call

Explanation: The verb 'call' is appropriate here as it indicates the action of naming or referring to something, fitting grammatically with the plural subject 'we' and the context of referring to the environments we inhabit.

Meaning: 'Call' means to name or refer to something, in this case, the environments that we consider our home.

Wrong options:

• get: 'Get' implies obtaining or receiving, which does not fit the context of naming or referring to environments.
• stay: 'Stay' means to remain in a place, which does not convey the intended meaning of referring to the environments we inhabit.
• pay: 'Pay' typically refers to giving money or attention, which does not align with the context of naming or referring.

Correct answer: reminder

Explanation: The noun 'reminder' fits perfectly as it indicates something that serves to make one remember a particular fact or situation, aligning with the purpose of the installation as stated in the sentence.

Meaning: 'Reminder' refers to something that prompts someone to remember something, in this case, the issue of plastic waste in oceans.

Wrong options:

• slider: 'Slider' refers to a mechanism for sliding, which does not relate to the context of raising awareness about pollution.
• divider: 'Divider' suggests something that separates, which does not match the purpose of the installation as a reminder.
• grinder: 'Grinder' refers to a tool for grinding, which is unrelated to the context of awareness and remembrance.

Correct answer: reduce

Explanation: The verb 'reduce' is the correct choice as it means to make something smaller or less in amount, fitting contextually with the goal of minimizing waste. It aligns with the imperative mood used in the sentence.

Meaning: 'Reduce' means to lessen or decrease something, in this case, the amount of waste produced.

Wrong options:

• allure: 'Allure' means to attract or tempt, which does not fit the context of minimizing waste.
• suit: 'Suit' means to be appropriate or fitting, which does not convey the action of decreasing waste.
• route: 'Route' refers to a path or course taken, which does not relate to the action of reducing waste.