在讲到Based on 用法有一个用法是Subject+verb+ Object based on..... 这个based on 修饰前面的Object 我能理解
但是后面一个例句: As a child Frank invented his own secret code, based on rebus-like puzzles and on the subsitution of numbers of letters.
为什么中间有个逗号这个句子也是对的啊?我觉得中间有了一个逗号,based on应该修饰 主语啊。。。求大神帮忙解答