Correct Answer: B

Rationale: To convert milligrams to grams, you need to divide by 1,000 because there are 1,000 milligrams in a gram. Therefore, 35,400 mg · 1,000 = 35.4 grams. Choice A is incorrect because it does not account for the conversion from milligrams to grams. Choice C is incorrect as it incorrectly drops a zero, leading to an inaccurate conversion. Choice D is incorrect as it incorrectly multiplies instead of dividing, resulting in a significantly larger value than the correct answer.

Correct Answer: B

Rationale: To convert 0.6 liters to milliliters, you need to multiply by 1000 since 1 liter equals 1000 milliliters. 0.6 * 1000 = 600 ml, which is the correct answer. Choice A (60 ml) is incorrect because it represents 0.06 liters. Choice C (6 ml) is incorrect as it would be the milliliter equivalent for 0.006 liters. Choice D (6000 ml) is incorrect as it would be the milliliter equivalent for 6 liters.

Correct Answer: A

Rationale: To convert milligrams to micrograms, you need to multiply by 1000. Therefore, 0.1 mg is equal to 100 mcg. This conversion is commonly used in medical calculations. Choice B (10 mcg) is incorrect because it would be the conversion from milligrams to micrograms if multiplied by 100, not 10. Choice C (1000 mcg) is incorrect as it would be the conversion from grams to micrograms if multiplied by 1000. Choice D (1 mcg) is incorrect as it represents the original unit without conversion.

Correct Answer: A

Rationale: To convert grams to kilograms, divide by 1,000 since there are 1,000 grams in a kilogram. Therefore, 34.5 grams · 1,000 = 0.0345 kilograms. The correct answer is 3.45 kg (not 3.45 grams, which is the amount given in the initial question). Choices B and C are incorrect as they do not involve the conversion from grams to kilograms. Choice D is also incorrect as it presents the value in grams instead of kilograms.

Correct Answer: B

Rationale: The metric system was developed in France during the 1790s as a standardized system of measurement. This choice is correct because the metric system originated in France. Germany, Italy, and Spain did not play a role in the development of the metric system, making choices A, C, and D incorrect.