1. The hormone responsible for milk production in the breasts after childbirth is:

A. Estrogen
B. Prolactin
C. Oxytocin
D. Relaxin

Correct answer: B

Rationale: The correct answer is B: Prolactin. Prolactin is the hormone responsible for milk production in the breasts after childbirth. It is produced by the pituitary gland and stimulates the alveoli in the breasts to produce milk. Estrogen plays a role in breast development during pregnancy but is not responsible for milk production. Oxytocin is responsible for the ejection of milk from the breasts during breastfeeding. Relaxin is a hormone that helps prepare the body for childbirth by relaxing the ligaments in the pelvis. Therefore, the hormone directly responsible for milk production after childbirth is prolactin.

2. What is the author's stance towards the idea of smart cities?

A. Strongly supportive, emphasizing only the benefits.
B. Strongly critical, focusing solely on the drawbacks.
C. Balanced and objective, highlighting both potential and concerns.
D. Indecisive and unclear about the overall value of smart cities.

Correct answer: C

Rationale: The passage acknowledges both the promise and challenges of smart cities, demonstrating a balanced perspective.

3. Which type of waves do not require a medium for propagation?

A. Transverse waves
B. Longitudinal waves
C. Electromagnetic waves
D. Surface waves

Correct answer: c

Rationale: Electromagnetic waves (such as light or radio waves) can travel through a vacuum as they do not require a medium.

4. Stephanie is often seen interacting with the medical intern during coffee breaks and after duty

A. Formal
B. Informal
C. Staff
D. Line

Correct answer: B

Rationale: The correct answer is 'B: Informal.' Stephanie's interactions with the medical intern during coffee breaks and after duty suggest a casual and friendly relationship, rather than a formal or official one. 'Informal' describes interactions that are relaxed, personal, and not bound by strict professional protocols. In contrast, 'formal' interactions would involve more structured and official communication, such as meetings or professional discussions. 'Staff' and 'line' are not relevant in this context, as they do not describe the nature of the relationship between Stephanie and the medical intern.

5. What is the general formula for an alkyl halide?

A. CnH2n
B. CnH2n+2
C. CnH2n-1X
D. CnH2nO

Correct answer: C

Rationale: The general formula for an alkyl halide is $C_nH_{2n-1}X$, where X represents a halogen (e.g., F, Cl, Br, I).

6. Vaccines work by:

A. Directly killing pathogens
B. Introducing weakened or inactive versions of pathogens to trigger immune response
C. Stimulating production of specific antibodies immediately
D. None of the above

Correct answer: B

Rationale: The correct answer is B: Introducing weakened or inactive versions of pathogens to trigger an immune response. Vaccines work by exposing the immune system to a harmless version of a pathogen, which allows the body to recognize and develop a defense against the pathogen without causing illness. This process stimulates the immune system to produce memory cells that can quickly recognize and attack the pathogen if encountered in the future. Vaccines do not directly kill pathogens (option A) or immediately stimulate the production of specific antibodies (option C). Therefore, option B is the most accurate description of how vaccines work.