Ключевые слова: background, biology, blue, book, carbon, close, closeup, concept, credit, ecological, ecology, education, educational, environment, flora, foliage, green, grow, growing, growth, hardcover, isolated, knowledge, leaf, learning, library, life, light, natural, nature, nobody, note, offset, open, paper, people, plant, sapling, science, seedling, shining, sky, sprout, textbook, tree, up, vertical, white, wisdom, world,