Correct Answer: A

Rationale: To convert from liters to milliliters, you need to multiply by 1000 since there are 1000 milliliters in a liter. Therefore, 0.5 liters x 1000 = 500 milliliters. This conversion is common in various contexts where different units of volume are used. Choices B, C, and D are incorrect as they do not reflect the correct conversion factor from liters to milliliters.

Correct Answer: B

Rationale: The correct answer is B: 128 ounces. One gallon is equivalent to 128 ounces. This conversion relationship is commonly used in cooking, baking, and various liquid measurements. Choice A (64 ounces) is incorrect as it represents half the amount of a gallon. Choice C (100 ounces) and Choice D (150 ounces) are also incorrect, as they do not accurately reflect the conversion of a gallon to ounces.

Correct Answer: B

Rationale: The base unit for mass in the metric system is grams. Grams are the fundamental unit of mass in the metric system, representing smaller quantities than kilograms and tons. Milligrams are a smaller unit of mass, kilograms are a larger unit, and tons are even larger units. Therefore, the correct choice is grams.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1,000 because there are 1,000 milliliters in 1 liter. Therefore, 3,540 liters 1,000 = 3,540,000 milliliters. Choices A, C, and D are incorrect because they do not correctly convert liters to milliliters. A, C, and D are off by a factor of 1,000, as they do not account for the conversion factor between liters and milliliters.

Correct Answer: B

Rationale: The decimal 0.2 is already at the nearest tenth, so it does not need to be rounded. Rounding to the nearest tenth means keeping one decimal place, which is already the case with 0.2. Therefore, the correct answer is 0.2, as it is already at the specified rounding point. Choices A, C, and D are incorrect because they represent values that are not the result of rounding 0.2 to the nearest tenth. 0.1 is rounding down, 0.3 is rounding up, and 0.25 is not the nearest tenth of 0.2.