I sat until after eleven， in a book.
A. absorbing
B. having absorbed
C. absorbed
D. having been absorbing
网友回答
A. absorbing
B. having absorbed
(答案→)C. absorbed
D. having been absorbing
解析：be absorbed in“集中注意力于……”，固定短语。此题中，absorbed的逻辑主语是I，所以用过去分词作伴随状语。