Correct Answer: A

Rationale: An equivalent fraction is a fraction that may look different in terms of its numerator and denominator but still represents the same value or quantity. This means that when you simplify or expand a fraction, its value remains unchanged. Choice B and C are incorrect because equivalent fractions are not determined by being smaller or larger than another fraction; it is about representing the same quantity. Choice D is incorrect because equivalent fractions may have different numerators as long as the ratio between the numerator and denominator remains the same.

Correct Answer: C

Rationale: The baby's measured weight is the dependent variable as it depends on the time intervals.

Correct Answer: D

Rationale: The correct answer is 25 g. Pencils are usually lightweight, and their weight is measured in grams. 25 kg (choice A) is too heavy for a pencil. 25 cm (choice B) is a unit of length, not weight. 25 mg (choice C) is too light for a pencil, as pencils typically weigh more than milligrams.

Correct Answer: C

Rationale: To convert milliliters (mL) to liters (L), you divide by 1000 since 1000 mL is equivalent to 1 liter. Therefore, 2500 mL is equal to 2.5 liters (2500 mL · 1000 = 2.5 L). Choice A (0.25 L) is incorrect as it represents a conversion error by a factor of 10. Choice B (25 L) is incorrect as it incorrectly multiplies instead of dividing by 1000. Choice D (250 L) is incorrect as it overestimates the conversion by a factor of 100.

Correct Answer: A

Rationale: To find the expression representing the length of the rectangle in terms of x, we need to consider that the length is six less than two times the width. If we denote the width as x, the length can be expressed as 2x - 6. Therefore, the correct expression is 2x-6 (choice A). Choice B, 6-2x, represents the width subtracted from 6, not the length. Choice C, 6x-2, is not derived from the given information about the relationship between the width and length. Choice D, 3x-4, is not consistent with the relationship provided in the question.