Meaning: 'Featured' means to have something prominently displayed or included, in this case, the photographs in the book about the kiwi.

Wrong options:

• taken: The word 'taken' implies that the photographs were captured but does not convey their inclusion in the book, making it contextually inappropriate here.
• brought: 'Brought' suggests an action of bringing something, which does not fit the context of describing the photographs' role in the book.
• crept: 'Crept' is a verb that means to move slowly and quietly, which is irrelevant in this context as it does not relate to the photographs at all.

Correct answer: since

Explanation: The word 'since' is appropriate here as it indicates a starting point in time, showing that Dr. Castro has been working with kiwi from the year 1999 to the present. This fits grammatically and contextually as it establishes a timeline for her work.

Meaning: 'Since' refers to a specific point in time when an action began and continues to the present, indicating the duration of Dr. Castro's work with kiwi.

Wrong options:

• at: 'At' is used to indicate a specific location or time but does not convey the ongoing nature of the work, making it grammatically incorrect in this context.
• with: 'With' indicates companionship or association but does not provide the temporal context needed here, thus failing to fit the sentence's meaning.
• before: 'Before' suggests a prior time but does not indicate continuity, which is essential in this context.

Correct answer: also

Explanation: The word 'also' is the correct choice as it adds an additional point to what Dr. Castro has been studying, indicating that her research includes both the sense of smell and interactions with the environment. This fits grammatically and contextually as it connects two related ideas.

Meaning: 'Also' means 'in addition' or 'too,' highlighting that there are multiple aspects being considered in her research.

Wrong options:

• and: 'And' is a conjunction that connects two clauses but does not convey the additional emphasis that 'also' provides, making it less suitable here.
• hence: 'Hence' indicates a conclusion or result, which does not fit the context of adding information about her research focus.
• therefore: 'Therefore' is used to indicate a conclusion drawn from previous statements, which does not align with the intent of adding another aspect of her study.

Correct answer: making

Explanation: The word 'making' is the correct choice as it indicates the process of creating or forming the introduction, fitting grammatically as a gerund that describes the action related to the book. It also aligns contextually with the idea of the book serving as an introduction.

Meaning: 'Making' refers to the act of creating or forming something, in this case, the introduction to the book about kiwi.

Wrong options:

• taking: 'Taking' implies an action of seizing or capturing, which does not fit the context of creating an introduction for the book.
• thinking: 'Thinking' refers to the process of considering or reflecting, which is irrelevant in the context of describing the book's introduction.
• calling: 'Calling' suggests naming or summoning, which does not relate to the act of creating an introduction, making it contextually inappropriate.

Correct answer: series

Explanation: The word 'series' is the correct choice as it indicates a collection of related works, fitting grammatically as a noun that describes the type of publication. It aligns contextually with the idea of multiple titles being published under a common theme.

Meaning: 'Series' refers to a set of related items or works published in succession, in this case, books about New Zealand's wildlife.

Wrong options:

• wedge: 'Wedge' refers to a triangular shape or tool and does not relate to the context of publications, making it irrelevant here.
• tokens: 'Tokens' typically refer to symbols or representations and do not fit the context of a collection of books, thus making it inappropriate.
• groups: 'Groups' suggests a collection but lacks the specific connotation of a sequential publication, making it less suitable than 'series'.