Meaning: 'Innovation' refers to the act of introducing something new or making changes to something established, particularly in technology or ideas.

Wrong options:

• riches: 'Riches' refers to wealth or abundance, which does not fit the context of discussing historical advancements.
• emerging: 'Emerging' is an adjective that describes something coming into view or becoming prominent, which does not fit as a noun in this context.
• remark: 'Remark' is a noun that refers to a comment or statement, which does not relate to the concept of historical advancements in inventions.
• iconic: 'Iconic' is an adjective that describes something as being widely recognized and well-established, which does not fit as a noun here.
• treats: 'Treats' is a noun that refers to enjoyable items or experiences, which does not relate to the context of history and innovation.
• first: 'First' is an adjective that indicates the initial occurrence of something, which does not fit as a noun in this context.

Correct answer: iconic

Explanation: The term 'iconic' serves as an adjective that describes the noun 'insulin,' emphasizing its significance and recognition in the medical field. It fits grammatically and contextually, highlighting the importance of insulin as a life-saving treatment.

Meaning: 'Iconic' means widely recognized and well-established, often representing something of great importance or significance.

Wrong options:

• riches: 'Riches' is a noun that refers to wealth, which does not describe insulin and is irrelevant in this context.
• emerging: 'Emerging' is an adjective that describes something coming into prominence, which does not fit as a descriptor for insulin's established status.
• remark: 'Remark' is a noun that refers to a comment, which does not appropriately describe insulin.
• treats: 'Treats' is a noun that refers to enjoyable items, which does not relate to the medical significance of insulin.
• innovation: 'Innovation' is a noun that refers to new ideas or inventions, which does not fit as a descriptor for insulin.
• first: 'First' is an adjective that indicates the initial occurrence, which does not describe insulin's established status.

Correct answer: emerging

Explanation: The word 'emerging' is an adjective that describes the hockey puck as something that was coming into prominence during the late 19th century. It fits grammatically and contextually, indicating the development of this crucial element of hockey.

Meaning: 'Emerging' refers to something that is coming into view or becoming prominent, particularly in a new or developing context.

Wrong options:

• riches: 'Riches' refers to wealth, which does not relate to the context of the hockey puck's development.
• remark: 'Remark' is a noun that refers to a comment, which does not fit as a descriptor for the hockey puck.
• iconic: 'Iconic' is an adjective that describes something as widely recognized, which does not fit the context of describing the timeline of the hockey puck's development.
• treats: 'Treats' is a noun that refers to enjoyable items, which does not relate to the context of the hockey puck.
• innovation: 'Innovation' is a noun that refers to new ideas or inventions, which does not fit grammatically as a descriptor for the hockey puck.
• first: 'First' is an adjective that indicates the initial occurrence, which does not fit in this context.

Correct answer: first

Explanation: The word 'first' is an adjective that describes the noun 'call,' indicating it was the initial call made by Alexander Graham Bell. It fits grammatically and contextually, emphasizing the significance of this event in the history of communication.

Meaning: 'First' refers to the initial occurrence of something, in this case, the first telephone call.

Wrong options:

• riches: 'Riches' refers to wealth, which does not relate to the context of making a call.
• emerging: 'Emerging' is an adjective that describes something coming into prominence, which does not fit as a descriptor for the initial call.
• remark: 'Remark' is a noun that refers to a comment, which does not fit in the context of describing a call.
• iconic: 'Iconic' is an adjective that describes something as widely recognized, which does not fit as a descriptor for the first call.
• treats: 'Treats' is a noun that refers to enjoyable items, which does not relate to the context of a telephone call.
• innovation: 'Innovation' is a noun that refers to new ideas or inventions, which does not fit grammatically as a descriptor for the call.