A.I. Explanation:

Correct answer: provided

Explanation: The word 'provided' fits grammatically as it indicates that chemical protection has offered or supplied effective control of crop losses. It aligns with the past tense context of the sentence, indicating an action that has been completed in recent years.

Meaning: 'Provided' means to supply or make available, indicating that chemical protection has made effective control of crop losses accessible.

Wrong options:

• harnessed: The term 'harnessed' implies controlling or using something effectively, but it does not fit the grammatical structure here as it suggests an active engagement rather than the provision of control.
• utilized: 'Utilized' means to make practical use of something, but it does not convey the same sense of offering or supplying control as 'provided' does in this context.
• offset: 'Offset' suggests counterbalancing or compensating for something, which does not align with the intended meaning of supplying effective control.

Correct answer: However

Explanation: The word 'However' serves as a discourse marker that introduces a contrast to the previous statement about the effectiveness of chemical protection. It indicates that despite the successes mentioned, there is a new need arising.

Meaning: 'However' means 'on the other hand' or 'nevertheless,' signaling a shift in the discussion to highlight a contrasting point.

Wrong options:

• Hopefully: 'Hopefully' expresses a desire for a positive outcome, which does not fit the context of introducing a contrasting need.
• Strangely: 'Strangely' implies something unusual or unexpected, which does not align with the logical flow of the argument being made.
• Therefore: 'Therefore' indicates a conclusion or result, which contradicts the need for a contrasting statement.

Correct answer: needed

Explanation: The word 'needed' fits grammatically and contextually as it indicates that alternatives to chemical pesticides are required. It aligns with the urgency expressed in the sentence regarding pesticide resistance and environmental concerns.

Meaning: 'Needed' means that something is required or necessary, emphasizing the importance of finding alternatives to chemical pesticides.

Wrong options:

• overshot: 'Overshot' means to exceed or go beyond, which does not fit the context of requiring alternatives.
• expired: 'Expired' suggests something that is no longer valid or has run out, which does not convey the necessity implied in the sentence.
• engaged: 'Engaged' means to be involved or occupied, which does not fit the context of needing alternatives.

Correct answer: Hence

Explanation: The word 'Hence' indicates a conclusion drawn from the previous statements about the need for complementary approaches. It fits grammatically and logically as it connects the reasoning for requiring these approaches to the context of pesticide use.

Meaning: 'Hence' means 'for this reason' or 'as a result,' indicating that complementary approaches are a necessary conclusion from the preceding discussion.

Wrong options:

• Though: 'Though' introduces a concession but does not fit the context of concluding a necessity, making it less appropriate here.
• Yet: 'Yet' implies a contrast but does not convey the same sense of conclusion as 'hence' does in this context.
• But: 'But' serves to contrast two ideas but does not effectively indicate a conclusion or result, which is what 'hence' does.