[Solved] Federal aid for transportation improvements, which accounted for more than 40% of the total in the 1960s and declined to about 20% in 1970, represents approximately what percentage of total federal aid today? A) About 5% B) About 10% C) About 15% D) About 25% Hardwood: Wood from dicot trees, typically denser and used for construction, furniture, and high-quality flooring. Gymnosperms: A collection of plants capable of producing seeds, encompassing conifers, cycads, Ginkgo, and gnetophytes, distinguished by their exposed or "naked" seeds. Water Potential: A measure of the potential energy in water, influencing the direction in which water will move, often used in the study of plant physiology. Vertically: In a direction or way that aligns or relates to the top and bottom or head and foot, typically in reference to genetics, to indicate transmission of traits from parent to offspring.