Foreign body partially obstructing the left main bronchus is likely to cause which of the following abnormalities:

Correct Answer: D

Rationale: A foreign body in the left main bronchus leads to air trapping on the left side, causing hyperinflation and shifting the mediastinum to the right on expiration. This results from a ball-valve effect, where air enters but cannot exit fully.

Correct Answer: A

Rationale: People often migrate from rural to urban areas in search of better educational facilities, which are typically more accessible in cities.

Correct Answer: B

Rationale: Rapid correction of hypernatremia can cause cerebral edema. The recommended safe correction rate is no more than 12 mmol/L per 24 hours.

Correct Answer: D

Rationale: In the uncompensated stage of shock, microvascular perfusion becomes marginal, leading to tissue hypoxia and metabolic acidosis.

Correct Answer: A

Rationale: Repeated exposure to ophthalmic medications can lead to contact allergy, characterized by redness, swelling, and itching.