【题目】— What kind of person do you think Tom is?
— He is a silent but hard-working student, always sitting there, a in the book he is reading.

【答案】absorbed
【解析】考查过去分词。句意：--你觉得Tom是什么样的人？--他是位安静但很勤奋的学生，总是坐在那完全投入地看书。空格处表示“投入”，故使用“absorbed”即可。