请教！！XDF蓝皮综合部分5

题目大概是说考古在N. campsite.发现了一只骨制笛，有四个洞，对应从第三至第六的音阶。七音阶是文艺复兴以来西方音乐采用的方法。结论是：七音阶法在西方音乐家采用以前已经发展并使用。

要支持。

正确答案：No musical instrument that is known to have used a diatomic scale is of an earlier date thatn the flute found at the N. campsite.

我选了：The cave-bear leg bone used to make the flute would have been long enough to make a flute capable of playing a complete distonic scale.

(难道这不是一个必要条件吗？为什么不正确？？)

求NN解答！谢谢！！