1. What is a potential limitation of using case studies in scientific research?

A. They offer unique insights and perspectives not found in large-scale studies.
B. They can be easily replicated and validated by other researchers.
C. They often present limited data points and may not be generalizable to larger populations.
D. They require sophisticated statistical analysis, making them difficult to interpret.

Correct answer: C

Rationale: While case studies provide valuable individual details, their small sample size and specific context limit their ability to represent broader trends or populations.

2. Which muscular pouch in the upper left abdomen stores food after swallowing and begins mechanical and chemical digestion?

A. Esophagus
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: B

Rationale: The correct answer is B: Stomach. The stomach is the muscular pouch in the upper left abdomen that stores food after swallowing. It is responsible for beginning both mechanical and chemical digestion processes. Once food enters the stomach, it is mixed with gastric juices and enzymes that break down the food into smaller particles. The stomach also contracts and relaxes to further mix the food with digestive juices. The esophagus is a tube that connects the throat to the stomach and does not store food or participate in digestion. The small intestine and large intestine are parts of the digestive system, but they are not muscular pouches in the upper left abdomen responsible for storing and digesting food.

3. Which sentence uses the present perfect continuous tense correctly?

A. I have been working on this project since morning.
B. She has finished the book already.
C. They will be leaving for vacation tomorrow.
D. He had been living in the city for ten years.

Correct answer: A

Rationale: Option A emphasizes the ongoing action (working) that started in the past and continues to the present.

4. What is the momentum of a car with a mass of 1500 kg moving at a speed of 20 m/s?

A. 30,000 kg m/s
B. 1500 kg m/s
C. 20 kg m/s
D. Momentum cannot be determined without knowing the direction of motion.

Correct answer: A

Rationale: Momentum is defined as the product of mass and velocity. Momentum = mass x velocity = 1500 kg x 20 m/s = 30,000 kg m/s.

5. What is the measure of the total amount of space occupied by an object?

A. Mass
B. Density
C. Weight
D. Volume

Correct answer: d

Rationale: Volume is the measure of the total amount of space occupied by an object and is typically measured in cubic units such as cubic meters or liters.