Meaning: 'Believe' means to accept something as true or to have faith in someone's abilities.

Wrong options:

• understanding: 'Understanding' is a gerund that does not function as a main verb in this context, making it grammatically incorrect here.
• think: 'Think' is a verb that could fit, but it does not convey the same strong conviction as 'believe' does in this context.
• completing: 'Completing' is a gerund that does not serve as a main verb and does not fit the grammatical structure of the sentence.
• build: 'Build' is a verb that does not relate to the belief being expressed and does not fit grammatically as the main verb here.
• solving: 'Solving' is a gerund that does not function as a main verb and does not fit the context of expressing belief.

Correct answer: understanding

Explanation: The word 'understanding' serves as a gerund that acts as the subject of the clause, indicating the action of comprehending the basis of information. It fits contextually as it relates to the process of gaining knowledge.

Meaning: 'Understanding' refers to the ability to grasp the meaning or significance of something.

Wrong options:

• think: 'Think' is a verb that does not fit grammatically as it cannot serve as the subject of the clause in this context.
• believe: 'Believe' is a verb that does not fit as it does not convey the action of comprehending the basis of information.
• completing: 'Completing' is a gerund that does not relate to the action of understanding and does not fit grammatically as the subject here.
• build: 'Build' is a verb that does not relate to the action of understanding and does not fit in this context.
• solving: 'Solving' is a gerund that does not convey the action of understanding and does not fit grammatically.

Correct answer: build

Explanation: The verb 'build' fits grammatically as it serves as the main verb in the future tense, indicating the action that participants will take to create their portfolio. It aligns with the context of developing skills and showcasing abilities.

Meaning: 'Build' means to create or develop something, in this case, a portfolio.

Wrong options:

• understanding: 'Understanding' is a gerund that does not function as a main verb in this context, making it grammatically incorrect here.
• think: 'Think' is a verb that does not relate to the action of creating a portfolio and does not fit grammatically as the main verb here.
• completing: 'Completing' is a gerund that does not serve as a main verb and does not fit the grammatical structure of the sentence.
• believe: 'Believe' is a verb that does not relate to the action of building a portfolio and does not fit in this context.
• solving: 'Solving' is a gerund that does not convey the action of building and does not fit grammatically.

Correct answer: completing

Explanation: The word 'completing' serves as a gerund that acts as the subject of the clause, indicating the action of finishing the program. It fits contextually as it relates to the culmination of the learning process.

Meaning: 'Completing' refers to the act of finishing or bringing something to an end.

Wrong options:

• think: 'Think' is a verb that does not fit grammatically as it cannot serve as the subject of the clause in this context.
• believe: 'Believe' is a verb that does not fit as it does not convey the action of finishing the program.
• understanding: 'Understanding' is a gerund that does not relate to the action of completing and does not fit grammatically as the subject here.
• build: 'Build' is a verb that does not relate to the action of completing and does not fit in this context.
• solving: 'Solving' is a gerund that does not convey the action of completing and does not fit grammatically.