Correct Answer: B

Rationale: The correct answer is B. Water is the most abundant nutrient in many foods. Water content varies across different foods, but in general, it is present in the highest amounts. Fats (
Choice
A) are essential but are not found in higher amounts compared to water. Proteins (
Choice
C) and carbohydrates (
Choice
D) are also important nutrients, but they are typically found in lower quantities in most foods compared to water.

Correct Answer: D

Rationale: The correct answer is D, Kilocalorie. The term kilocalorie, often referred to as a calorie, is the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius. While
Choice A, Calorie, is technically correct, it is not the most specific term for the described amount of heat.
Choice B, Joule, is a unit of energy but not specifically related to the amount of heat required to raise the temperature of water.
Choice C, Kilojoule, is also a unit of energy but not the precise term for the heat required to raise the temperature of water by one degree Celsius.

Correct Answer: B

Rationale: Skin rash or hives are common signs of an allergic reaction in children, often following exposure to allergens. While a persistent cough can occur in some cases, it is not typically a primary sign of an allergic reaction. Increased appetite is unrelated to allergic reactions. A low-grade fever is not a common sign of an allergic reaction but can be present in other conditions like infections.

Correct Answer: D

Rationale: The correct approach in a scientific experiment is to prevent yourself from knowing the contents of the pill bottles and distribute them randomly to the subjects. This randomization helps to avoid bias and ensures that the results are not influenced by preconceived notions. Option A is incorrect because it introduces gender bias by assigning pills based on gender. Option B is incorrect as it mentions telling the subjects what they are getting, which could lead to placebo effects. Option C is incorrect as it suggests disclosing group information to the subjects, which can also introduce bias.

Correct Answer: B

Rationale: Limited range of motion in the hip, often noted as a limitation in abduction, is a common sign of congenital hip dysplasia. This limitation is due to the abnormal development of the hip joint, affecting its movement. Symmetrical hip movement (
Choice
A) is not a characteristic sign of congenital hip dysplasia. Swelling of the knees (
Choice
C) is not typically associated with this condition. Dislocated patella (
Choice
D) refers to a different anatomical structure and is not a common sign of congenital hip dysplasia.