在AF上找到答案了
“I’ve heard people treat COGS as some sort of cash flow. Mind you, it is an Income Statement expense and also may show up in the Balance Sheet; it is not part of the Cash Flow Statements. I guess some people think simplistically about COGS as they do in everyday life; you pay cash for something that you later sell. Turns out it is simply not part of the CF statements and this ‘expense’ may or may not have been paid with cash. ”

cash tax is lower

多谢jessica！刚在analyst forum找到比较完整的回答，现在明白了。

教材上有哈