Correct Answer: B

Rationale: To convert 0.1 liter to milliliters, you need to multiply by 1000 because there are 1000 milliliters in a liter. Therefore, 0.1 liter converts to 100 milliliters. Choice A (10 ml) is incorrect as it represents 0.01 liters, not 0.1 liters. Choice C (1000 ml) is incorrect as it represents 1 liter, not 0.1 liters. Choice D (1 ml) is incorrect as it is too small a quantity for 0.1 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: B

Rationale: The prefix 'centi' means 0.01, which is one-hundredth of the base unit. For example, 1 centimeter is equal to 0.01 meters. Choice A (0.1) is incorrect as it represents 'deci,' which means one-tenth. Choice C (0.001) is incorrect as it represents 'milli,' which means one-thousandth. Choice D (1) is incorrect as it is not a valid interpretation of the prefix 'centi.' Therefore, the correct answer is B.

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: To convert meters to kilometers, the conversion factor is 1 kilometer = 1,000 meters. Therefore, to find how many kilometers are in 1,000 meters, you divide 1,000 by 1,000, which equals 1 kilometer. Choice A (0.1 km), Choice C (10 km), and Choice D (0.01 km) are incorrect because they do not correctly represent the conversion of 1,000 meters to kilometers.