彩虹在英文中的读法是"Rainbow"，这是一个非常常见的词汇，指的是在雨后天空中出现的一道由七种颜色组成的弧形光带，这七种颜色通常按照红、橙、黄、绿、蓝、靛、紫的顺序排列，彩虹的形成是由于阳光照射到雨滴上，然后被折射和反射形成的。
如果你想用更复杂的句子来描述彩虹，你可以说："A rainbow is a beautiful natural phenomenon that appears after a rain shower. It is made up of seven colors, which are red, orange, yellow, green, blue, indigo and violet, and appears as a curved line in the sky."
