Correct Answer: A

Rationale: To convert liters to milliliters, you need to multiply by 1000 since 1 liter is equal to 1000 milliliters. Therefore, 0.5 liters multiplied by 1000 equals 500 milliliters. Choice A, 500 mL, is the correct answer. Choice B, 50 mL, is incorrect as it represents converting 0.05 liters to milliliters. Choice C, 5 mL, is incorrect as it represents converting 0.005 liters to milliliters. Choice D, 0.5 mL, is incorrect as it represents the original amount in milliliters, not the conversion of liters to milliliters.

Correct Answer: A

Rationale: To convert grams to milligrams, you need to multiply by 1000, not 10000. Therefore, to convert 0.04 grams to milligrams, you multiply 0.04 by 1000, which equals 40 mg. Choice A (40 mg) is the correct answer. Choice B (4 mg) is incorrect as it represents converting 0.004 grams to milligrams. Choice C (400 mg) is incorrect as it is 10 times the correct conversion. Choice D (0.4 mg) is incorrect as it is 10 times smaller than the correct conversion.

Correct Answer: B

Rationale: To convert grams to kilograms, you divide by 1,000 since there are 1,000 grams in a kilogram. Therefore, 1,500 grams divided by 1,000 equals 1.5 kilograms, making choice B the correct answer. Choices A, C, and D are incorrect because they do not correctly convert grams to kilograms.

Correct Answer: A

Rationale: To convert liters to milliliters, you need to multiply by 1,000 since there are 1,000 milliliters in a liter. So, to convert 0.04 liters to milliliters, you would multiply 0.04 by 1,000, giving you 40 milliliters. This means that choice A, '40 ml', is the correct answer. Choices B, C, and D are incorrect because they do not correctly convert liters to milliliters. Choice B, '4 ml', is incorrect as it is 10 times smaller than the correct conversion. Choice C, '400 ml', is incorrect as it is 10 times larger than the correct conversion. Choice D, '0.4 ml', is incorrect as it is one-tenth of the correct conversion.

Correct Answer: B

Rationale: To convert 0.2 liters to milliliters, you need to multiply by 1,000 because there are 1,000 milliliters in a liter. So, 0.2 * 1,000 = 200 milliliters. Therefore, the correct answer is 200 ml. Choice A (20 ml) is incorrect because it represents 0.02 liters, not 0.2 liters. Choice C (2 ml) is incorrect as it represents 0.002 liters. Choice D (2000 ml) is incorrect as it represents 2 liters, not 0.2 liters.