Which drug is most likely to cause muscle tremor:

Correct Answer: B

Rationale: The correct answer is B: Terbutaline. Terbutaline is a beta-2 adrenergic agonist used as a bronchodilator. It can stimulate beta-2 receptors in skeletal muscle, leading to muscle tremors as a common side effect. Ipratropium (A) is an anticholinergic bronchodilator and typically does not cause muscle tremors. Atenolol (C) is a beta-blocker and is not associated with muscle tremors. Nicotinic acid (D) is used to treat dyslipidemia and does not commonly cause muscle tremors. Therefore, Terbutaline is the most likely drug to cause muscle tremor among the options provided.

Correct Answer: C

Rationale: The correct answer is C (21, 0.04, high). This composition represents the approximate percentage of oxygen (21%) and carbon dioxide (0.04%) in the air inside the balloons. Oxygen is a major component of the air we breathe, making up around 21% of the atmosphere. Carbon dioxide, on the other hand, is present in trace amounts, about 0.04%. The other choices are incorrect because they do not accurately represent the typical composition of air. Choice A has a low oxygen content and choice B has a high carbon dioxide content, both of which do not align with the usual composition of the air. Choice D also has a low oxygen content and high carbon dioxide content, making it incorrect.

Correct Answer: C

Rationale: The correct answer is C because in a fuel cell, the chemical product is water (H2O) produced from the reaction of hydrogen and oxygen, and the energy used to power the vehicles is electrical energy generated from the electrochemical reaction in the fuel cell. Choice A (hydrogen, electrical) is incorrect because hydrogen is the input fuel, not the output product. Choice B (hydrogen, thermal) is incorrect because thermal energy is not the primary form of energy produced in a fuel cell. Choice D (water, thermal) is incorrect because while water is the product, the energy produced is electrical, not thermal.

Correct Answer: D

Rationale: The correct answer is D: 600 cm/s. The speed of a wave is determined by the formula speed = frequency x wavelength. Given that the frequency and wavelength are constant, the only way to increase the speed is to increase the frequency or the wavelength. Since both frequency and wavelength are fixed, the speed can only be increased by increasing both. Choice D, 600 cm/s, is double the speed of choice C, 300 cm/s, which indicates that both frequency and wavelength have been doubled, leading to the correct answer. Choices A and B are too low to be correct, as they are not consistent with the principles of wave speed calculation.

Correct Answer: B

Rationale: The correct answer is B: steroid hormones. Steroid hormones are known to regulate gene expression by binding to specific receptors and influencing transcription processes. They can directly affect the transcription of new messenger RNA in the cell. Pancreatic hormones (A), catecholamines (C), and pituitary gland hormones (D) are not directly involved in the transcription of new messenger RNA. Pancreatic hormones primarily regulate blood sugar levels, catecholamines are involved in the fight-or-flight response, and pituitary gland hormones regulate various functions such as growth, reproduction, and metabolism.