Correct Answer: A

Rationale: The correct answer is 'A: Breathe.' When a child has a stuffy nose, the difficulty they experience is related to the action of breathing. 'Breathing' (choice B) is a gerund and doesn't fit the context of the question. 'Breath' (choice C) is a noun, not the correct verb form. 'Breadth' (choice D) refers to the extent or width of something and is unrelated to the child's difficulty due to a stuffy nose.

Correct Answer: D

Rationale: The correct answer is 'D: Basic.' In this context, 'fundamental' means basic or essential, referring to the core or foundational dissimilarity between the two medications. Choice A, 'Appropriate,' is incorrect as it does not reflect the meaning of 'fundamental' in this sentence. Choice B, 'Underlying,' is incorrect because although it is related, it does not capture the primary or essential nature of the difference being discussed. Choice C, 'Dosage,' is unrelated to the meaning of 'fundamental' and does not align with the context of the sentence.

Correct Answer: B

Rationale: 'Biologists' is a noun in the sentence, referring to a group of people who study wildlife and their behaviors. In this context, 'biologists' is not describing or modifying another noun, making it a noun itself. Therefore, options A, C, and D are incorrect.

Correct Answer: C

Rationale: The correct answer is 'Democratic.' A 'Democratic' leadership style involves the leader being open to new ideas and thoughts from the group and encourages group participation in decision-making. This style promotes collaboration, communication, and inclusivity in decision-making processes. 'Laissez-faire' leadership is characterized by a hands-off approach with minimal guidance or direction. 'Autocratic' leadership is where the leader makes decisions without much input from the group. 'Direct' leadership is not a widely recognized leadership style in this context.

Correct Answer: A

Rationale: The correct answer is A, 'Complex.' The term 'convoluted' is used to describe something that is intricate, complex, or twisted. 'Clever' (choice B) means showing intelligence or skill, 'Candid' (choice C) means truthful and straightforward, and 'Asinine' (choice D) means extremely foolish or silly. These choices do not accurately reflect the meaning of 'convoluted.'