Correct Answer: A

Rationale: The correct answer is 'meter.' In the metric system, 'm' stands for meter, which is the base unit for length. Choice B, 'mole,' is a unit used in chemistry to represent an amount of substance. Choice C, 'milli,' represents a prefix indicating one-thousandth, and choice D, 'micro,' represents a prefix indicating one-millionth. Therefore, the correct choice is 'A: meter.'

Correct Answer: A

Rationale: The prefixes 'micro-' and 'milli-' represent 10^-6 and 10^-3, respectively. 'Micro-' denotes one-millionth (10^-6), while 'milli-' denotes one-thousandth (10^-3). Choice B is incorrect because it confuses the order of magnitudes for micro and milli. Choice C and D are also incorrect as they provide the wrong values for the prefixes micro and milli.

Correct Answer: A

Rationale: In the metric system, 'km' stands for kilometer, which is a unit of length equal to 1,000 meters. This choice is correct as 'kilometer' is the standard unit for measuring long distances. Choice B, 'kilomole,' is incorrect as it is a unit in chemistry representing a quantity of substance. Choice C, 'kilobyte,' is incorrect as it is a unit of digital information storage, not a unit of measurement. Choice D, 'knot,' is incorrect as it is a unit of speed used in navigation and aeronautics, not a unit of length in the metric system.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply the number of liters by 1000 because there are 1000 milliliters in 1 liter. Therefore, 0.5 liters converts to 500 milliliters. Choice A (50 ml) is incorrect as it is the result of multiplying by 10 instead of 1000. Choice C (5 ml) is incorrect as it is the result of dividing by 10 instead of multiplying by 1000. Choice D (0.5 ml) is incorrect as it represents the original quantity in milliliters, not the conversion from liters.

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.