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.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1,000 since there are 1,000 milliliters in a liter. Therefore, 0.09 liters x 1,000 = 90 milliliters. Choice A, 0.09 ml, is incorrect as it represents the original volume in milliliters. Choices C and D, 900 ml and 9 ml, are incorrect as they miscalculate the conversion from liters to milliliters.

Correct Answer: B

Rationale: One pint is equivalent to 2 cups. This conversion is a common measurement in cooking and baking. Choice A (1 cup), Choice C (3 cups), and Choice D (4 cups) are incorrect because a pint specifically contains 2 cups according to standard measurement conversions.

Correct Answer: A

Rationale: To convert liters to milliliters, you need to multiply by 1000 since there are 1000 milliliters in a liter. Therefore, 0.5 liters is equal to 500 milliliters. Choices B, C, and D are incorrect because they do not reflect the correct conversion from liters to milliliters.

Correct Answer: B

Rationale: To convert kilometers to meters, you need to multiply by 1,000 since there are 1,000 meters in a kilometer. Therefore, 345 km multiplied by 1,000 equals 345,000 meters. Choice A is incorrect as it incorrectly places the comma. Choice C is incorrect as it adds an extra zero at the end. Choice D is incorrect as it adds an extra zero at the beginning, resulting in an incorrect conversion.