When I arrived,everybody was sitting around the table and talking.Their mouths were empty,but their stomachs were full.They ___________.
1.had been eating
2.had eaten
请问一下，这里答案给1.，可是我觉得文法上2.也通，请问可以用had eaten 来使用吗？谢谢大大们!!!

过去完成进行式=进行式的过去完成 不是过去完成的进行式(过去完成是没有进行式的) 必须要知道这一点简单说就是 They were eating. 变成了完成式而不是 They ate. 变成了完成式选1表示 我来之前他们正在吃东西 (最合理)

其实这题出处是要跟过去进行做比较题目改成这样不是很恰当

谢谢两位大大!!