Untitled AI art by @friendly-alliance2

Create a bold and eye-catching ebook cover with dimensions 1600x2400 pixels, for a professional English learning book. The title "100 exercícios de inglês" should appear at the top of the cover in Montserrat font, large and highly visible. Just below it, add the subtitle "Aprenda praticando" in Arial font, slightly smaller. In the center of the cover, place a realistic and vibrant image of the United States flag, waving or dynamically positioned. At the bottom of the cover, include the author's name: "English Time" in a clean, professional font. Use a modern, clean layout with high contrast and professional colors. Ensure all elements are visually balanced and optimized for a digital ebook format.