Correct Answer: A

Rationale: The correct answer is plant fats (Choice A). Fats, including plant fats, provide 9 kcalories per gram, which is more than 4 kcalories. Plant proteins (Choice B) and animal proteins (Choice C) provide 4 kcalories per gram. Plant carbohydrates (Choice D) also provide 4 kcalories per gram. Therefore, Choices B, C, and D are incorrect because they do not yield more than 4 kcalories per gram.

Correct Answer: C

Rationale: When an increase in exercise is accompanied by a decrease in body weight, it demonstrates a negative correlation. This means that as one variable (exercise) increases, the other variable (body weight) decreases. Choice A, 'variable effect,' is vague and does not accurately describe the relationship between exercise and body weight. Choice B, 'positive correlation,' is incorrect because in a positive correlation, both variables would increase or decrease together. Choice D, 'randomization effect,' is unrelated to the scenario described.

Correct Answer: B

Rationale: The correct answer is B: Daily chest physiotherapy. Daily chest physiotherapy is essential in cystic fibrosis as it helps in clearing mucus from the lungs, reducing the frequency of respiratory infections. Antibiotics (Choice A) may treat infections but are not the key preventive measure. Increased fluid intake (Choice C) and dietary supplements (Choice D) can be beneficial for overall health but do not directly prevent recurrent respiratory infections in children with cystic fibrosis.

Correct Answer: B

Rationale: Rapid breathing is a common sign of a respiratory infection in infants. When infants have a respiratory infection, their breathing may become rapid as their body tries to get more oxygen. This symptom is often seen alongside cough and fever. Increased appetite (Choice A) is not typically associated with respiratory infections but can be seen in other conditions. Decreased urine output (Choice C) is more indicative of dehydration or kidney issues rather than a respiratory infection. Lethargy (Choice D) can be a symptom of various illnesses but is not as specific to respiratory infections as rapid breathing.

Correct Answer: A

Rationale: Food energy is commonly expressed in kilocalories and kilojoules. Kilocalories and kilojoules are both units of energy commonly used to measure the energy content of food. Kilograms, kilometers, and kilonewtons are units of mass, distance, and force, respectively, and are not used to express food energy.