Meaning: 'Release' means to allow something to escape or to set free, in this case referring to the emission of harmful gases into the environment.

Wrong options:

• lease: Lease refers to a contractual agreement for renting property, which does not fit the context of gas emissions.
• tease: Tease means to make fun of or provoke someone playfully, which is unrelated to the topic of gas release.
• cease: Cease means to stop or bring to an end, which contradicts the intended meaning of gases being emitted.

Correct answer: disperse

Explanation: The word 'disperse' is the correct verb that describes the action of spreading out over a wide area, which is appropriate in the context of how acids travel due to wind patterns. It fits grammatically as it is used in the present tense to describe an ongoing action.

Meaning: 'Disperse' means to distribute or spread over a wide area, which accurately describes how the acids move through the atmosphere.

Wrong options:

• dispose: Dispose means to get rid of something, which does not fit the context of how acids spread in the environment.
• disapprove: Disapprove means to have an unfavorable opinion, which is irrelevant to the action of acids moving through the air.
• disposition: Disposition refers to a person's inherent qualities of mind and character, which does not relate to the action of spreading.

Correct answer: such

Explanation: The word 'such' is used here as a determiner to refer back to the previously mentioned concept of man-made acid deposition, indicating that it is an example of a broader category. It fits grammatically and contextually as it introduces a specific instance of the general topic discussed.

Meaning: 'Such' means of the type previously mentioned, in this case referring to the specific issue of acid deposition caused by human activities.

Wrong options:

• saying: Saying is a gerund form that does not fit grammatically in this context, as it does not serve as a determiner or reference.
• part: Part is a noun that does not appropriately connect to the previous sentence's context about acid deposition.
• evidence: Evidence is a noun that refers to proof or support for a claim, which does not fit the grammatical structure needed here.

Correct answer: further

Explanation: The word 'further' is an adverb that indicates an increase in degree or extent, which is appropriate in the context of public attention growing over time. It fits grammatically as it modifies the verb 'increased' to describe the extent of the increase.

Meaning: 'Further' means to a greater degree or extent, indicating that public attention became more pronounced during the 1970s.

Wrong options:

• inadvertently: Inadvertently means unintentionally, which does not fit the context of public attention increasing purposefully.
• geometrically: Geometrically refers to a mathematical concept of shapes and sizes, which is irrelevant to the context of public attention.
• comprehensively: Comprehensively means in a thorough way, which does not accurately describe the nature of the increase in public attention.