Correct Answer: B

Rationale: The Becquerel (Bq) is the unit used to measure radioactivity, specifically the activity of a quantity of radioactive material. It represents the number of radioactive disintegrations or transformations per unit of time. Choice A, electron volt (eV), is a unit of energy, not radioactivity. Choice C, electric charge (Coulombs), is measured in Coulombs, not Becquerels. Choice D, force (Newtons), is a unit of force, not radioactivity. Therefore, the correct answer is B.

Correct Answer: C

Rationale: The correct answer is C, the stomach. The stomach is responsible for churning and mechanically breaking down food. It contains muscles that contract and relax to mix food with digestive juices, breaking it down into smaller particles. This mechanical digestion process helps prepare the food for further digestion and absorption in the small intestine. The small intestine is primarily responsible for the absorption of nutrients, not for mechanical digestion. The large intestine absorbs water and salts, and the esophagus is a muscular tube that transports food from the mouth to the stomach, not involved in churning or breaking down food.

Correct Answer: C

Rationale: The main force propelling the rocket upwards is the thrust from the rocket engine. Thrust is the force produced by the rocket engine pushing exhaust gases in the opposite direction, following Newton's third law of motion (action and reaction). This thrust overcomes the force of gravity and allows the rocket to lift off and move upwards. Choice A, gravitational force, is incorrect as gravity pulls objects towards the Earth, and in this case, the rocket is moving against gravity. Choice B, air resistance, is incorrect because it opposes the motion of the rocket and is more relevant during descent rather than ascent. Choice D, normal force from the launchpad, is incorrect as this force acts perpendicular to the surface and does not propel the rocket upwards.

Correct Answer: A

Rationale: Desquamation is the correct term for the shedding of the outermost layer of the epidermis. This process is essential for skin renewal, allowing the removal of dead skin cells from the skin's surface. Exfoliation, on the other hand, involves the removal of dead skin cells through mechanical or chemical methods. Keratinization refers to the process where skin cells produce the protein keratin, contributing to the skin's protective barrier. Epidermolysis is a condition characterized by the separation of the epidermis from the dermis due to a structural defect in the skin.

Correct Answer: A

Rationale: The correct answer is A: Ventral carries motor, dorsal carries sensory information. In the spinal nerve, the ventral root carries motor information from the spinal cord to the muscles, while the dorsal root carries sensory information from the peripheral sensory receptors to the spinal cord. Therefore, other choices are incorrect. Choice B is incorrect as it states the opposite roles of ventral and dorsal roots. Choice C is incorrect as the size comparison between ventral and dorsal roots is not related to their functions. Choice D is incorrect as the terms 'anteriorly' and 'posteriorly' are not commonly used to describe the locations of ventral and dorsal roots in relation to each other.