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: A

Rationale: 0.5 liters is equivalent to 500 milliliters. This conversion is straightforward because 1 liter equals 1000 milliliters. Choice A is correct because it accurately converts 0.5 liters into milliliters. Choices B, C, and D are incorrect as they do not correctly convert the given volume into milliliters.

Correct Answer: C

Rationale: The correct answer is C: 10^12. Tera represents a numerical value of 10^12, which is equivalent to one trillion. It is commonly used in computing and other fields to denote large-scale measurements. Choice A, 10^6, is incorrect as it corresponds to the metric prefix 'Mega.' Choice B, 10^9, is incorrect and corresponds to the metric prefix 'Giga.' Choice D, 10^3, is incorrect and corresponds to the metric prefix 'Kilo.' Therefore, the correct interpretation of the metric prefix Tera is 10^12.

Correct Answer: A

Rationale: To convert 0.26 to a fraction, we write it as 26/100. To simplify this fraction, we divide both the numerator and the denominator by their greatest common divisor, which is 2 in this case. Dividing 26 and 100 by 2 results in 13/50. Therefore, 0.26 as a fraction in simplest form is 13/50. Choice B (26/100) is the original form of the decimal, not simplified. Choice C (26/1000) is incorrect as it doesn't match the decimal representation. Choice D (1/4) is not the equivalent fraction for 0.26.

Correct Answer: A

Rationale: The correct answer is A: 1760 yards. There are 1760 yards in one mile. This conversion is a standard unit of measurement in the imperial system. Choice B, 1500 yards, is incorrect as it is not the correct conversion from miles to yards. Choice C, 2000 yards, is also incorrect as it does not represent the accurate conversion. Choice D, 1800 yards, is incorrect as it does not reflect the correct number of yards in a mile according to the established conversion rate.