在曼哈顿上看到过Ron写的一个句子 这是您所说的“两个同时修饰同一个句子的adv. modifiers就那么用逗号串联“
Coming home from school, riding my bike, I was knocked down by the wind.
here, "coming home from school" and "riding my bike" are both genuinely initial modifiers, attempting to describe "I".