Correct Answer: A

Rationale: To convert 0.6 liters to milliliters, you need to multiply by 1,000 since there are 1,000 milliliters in a liter. Therefore, 0.6 liters equals 600 milliliters. Choice B (60 ml) is incorrect as it is a conversion of 0.06 liters, not 0.6 liters. Choice C (6 ml) is incorrect as it represents a conversion of 0.006 liters, not 0.6 liters. Choice D (0.6 ml) is incorrect as it is the original amount in milliliters, not the converted amount from liters.

Correct Answer: A

Rationale: In the metric system, 'L' stands for liter, which is the base unit for liquid volume. The other choices are incorrect: 'B' log is not a standard metric unit, 'C' link is a unit of length in the Imperial system, and 'D' lever is not a metric unit but a simple machine.

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: B

Rationale: To convert milliliters to liters, you need to divide by 1,000 since there are 1,000 milliliters in a liter. Therefore, 3,450 mL · 1,000 = 3.45 liters. Choice A (0.345 liters) is incorrect as it incorrectly moves the decimal point. Choice C (34.5 liters) is incorrect as it overestimates the conversion. Choice D (345 liters) is incorrect as it overestimates by an order of magnitude.

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.