“They say you're a very good chess player.”

“Well, I have been playing ____ many years, but I am hardly an expert.”

A. since    B. during    C. for    D. from (TOEFL)

答案为C，刚开始以many排除了B (during)，英语常见问题解答也解释道“for是指持续时间的长短，回答how long?(多长时间？)的问题，而during则是指动作所发生的时间，回答when?(什么时候？)的问题”

但是随后在韦氏高阶里找到：

• The camp has changed a lot over the years. [= during several / some / many years] .

请问老师们这里during怎么理解。如果during many years的意思也可以是over the years，那考题用during似乎也能翻译的出来, 在这几年中我一直在下棋...(临时习惯)。