Meaning: 'Emissions' refers to the gases or pollutants released into the air, particularly from sources like vehicles or factories, which contribute to climate change.

Wrong options:

• visits: 'Visits' refers to the act of going to see someone or something, which does not relate to energy or greenhouse gases.
• suspicious: 'Suspicious' describes a feeling of distrust or doubt, which is irrelevant in this context about energy and emissions.
• medals: 'Medals' are awards given for achievement, which does not connect to the topic of energy use or environmental impact.

Correct answer: households

Explanation: The word 'households' is a plural noun that refers to groups of people living together, which is contextually appropriate as the text discusses ways to encourage these groups to use less energy.

Meaning: 'Households' means the people living in a single home or residence, often used in discussions about energy consumption and social studies.

Wrong options:

• gauchos: 'Gauchos' refers to South American cowhands, which is unrelated to the context of energy use.
• cowpokes: 'Cowpokes' is a colloquial term for cowboys, which does not fit the context of energy consumption.
• outgrowths: 'Outgrowths' refers to something that has developed from something else, which does not apply to the discussion of energy use.

Correct answer: phenomenon

Explanation: The word 'phenomenon' is a noun that describes an observable event or occurrence, which fits well in the context of discussing the effects of being observed on behavior.

Meaning: 'Phenomenon' means an observable fact or event, especially one that is unusual or difficult to explain, in this case, the change in behavior due to observation.

Wrong options:

• meme: 'Meme' refers to an idea or behavior that spreads within a culture, which does not relate to the context of energy use and behavior change.
• supermom: 'Supermom' is a colloquial term for an exceptionally capable mother, which is irrelevant in this context.
• orangutang: 'Orangutang' is a type of primate, which does not connect to the topic of human behavior and energy consumption.

Correct answer: Hawthorne

Explanation: The term 'Hawthorne' is a proper noun referring to the specific effect named after the Hawthorne studies, which is relevant to the context of behavioral changes due to observation.

Meaning: 'Hawthorne' refers to the Hawthorne effect, which describes how individuals modify their behavior when they know they are being observed.

Wrong options:

• Soapstone: 'Soapstone' is a type of metamorphic rock, which does not relate to the context of behavioral studies.
• Jawbone: 'Jawbone' refers to the bone structure of the jaw, which is irrelevant in this context.
• Longhorn: 'Longhorn' typically refers to a breed of cattle, which does not connect to the topic of behavioral observation.

Correct answer: researchers

Explanation: The word 'researchers' is a plural noun that refers to individuals conducting studies, fitting well in the context of the sentence discussing the study of the Hawthorne effect.

Meaning: 'Researchers' are people who conduct investigations or studies to discover new information, particularly in scientific fields.

Wrong options:

• lurch: 'Lurch' means to make an abrupt or uncontrolled movement, which does not fit the context of conducting research.
• substitutes: 'Substitutes' refers to replacements, which does not apply to the context of individuals conducting a study.
• undershirt: 'Undershirt' is a type of clothing worn under a shirt, which is irrelevant in this context.

Correct answer: monitored

Explanation: The word 'monitored' is the past tense of the verb 'monitor,' meaning to observe and check the progress or quality of something over a period of time, which fits the context of the study being discussed.

Meaning: 'Monitored' means to observe and check the behavior or performance of something, particularly in a systematic way, as in the study of energy use.

Wrong options:

• satirised: 'Satirised' means to mock or ridicule, which does not fit the context of observing energy use.
• manacled: 'Manacled' means to be shackled or restrained, which is irrelevant in the context of monitoring energy consumption.
• monocled: 'Monocled' refers to wearing a monocle, which is unrelated to the act of observing or studying.