Correct Answer: B

Rationale: To convert milliliters to liters, you need to divide by 1000 since 1 liter is equal to 1000 milliliters. Therefore, 500 milliliters divided by 1000 equals 0.5 liters. Choice A (0.05 liters) is incorrect because it represents 50 milliliters, not 500 milliliters. Choice C (5 liters) and Choice D (50 liters) are both incorrect as they are higher values and do not accurately represent the conversion of 500 milliliters to liters.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1000, not 10000. Therefore, 0.2 liters equals 200 ml (0.2 x 1000 = 200 ml). Choice A, 20 ml, is incorrect because it's the result of multiplying by 10 instead of 1000. Choice C, 2 ml, is incorrect as it's the result of ignoring the decimal point. Choice D, 2000 ml, is incorrect because it's the result of multiplying by 10000.

Correct Answer: B

Rationale: To convert centimeters to millimeters, you multiply by 10 since there are 10 millimeters in a centimeter. Therefore, 5 centimeters x 10 = 50 millimeters, making choice A the correct answer. Choice C, '5 mm,' is incorrect as it represents the original quantity in millimeters. Choice D, '500 cm,' is incorrect as it converts the centimeters to centimeters instead of millimeters.

Correct Answer: A

Rationale: In the metric system, 'cm' stands for centimeter, which is a unit of length equal to 1/100th of a meter. The correct answer is 'centimeter' (A). Choice B, 'cubic meter,' is a unit of volume, not length. Choice C, 'cord,' is not a standard metric unit. Choice D, 'centi,' is a prefix meaning one-hundredth, but 'cm' specifically stands for centimeter, not just the prefix.

Correct Answer: A

Rationale: The correct answer is A: 0.3 ml. To convert milligrams (mg) to milliliters (ml), you typically need the substance's density. However, in many medical contexts, especially with liquid medications similar in density to water, 0.3 mg is commonly assumed to be equivalent to 0.3 ml. Choice B (3 ml) is incorrect as it is 10 times greater than the correct conversion. Choice C (30 ml) is incorrect as it is 100 times greater than the correct conversion. Choice D (0.03 ml) is incorrect as it is one-tenth of the correct conversion.