问题补充：
Entering the reading room, .
A. Mike and Tom were found seated quietly, doing their homework
B. Mike and Tom were found seating quietly, doing their homework
C. he found Mike and Tom seating quietly, doing their homework
D. he found Mike and Tom seated quietly, doing their homework
答案：
A. Mike and Tom were found seated quietly, doing their homework
B. Mike and Tom were found seating quietly, doing their homework
C. he found Mike and Tom seating quietly, doing their homework
(答案→)D. he found Mike and Tom seated quietly, doing their homework
解析：考查非谓语动词。分词的逻辑主语应与句子的主语保持一致。根据语境进入的阅览室的动作应由he来执行，动词seat 坐，没有动名词形式seating，只有过去分词的形式seated，所以选D，seated作宾补，doing作伴随状语，句意：进入阅览室，他发现迈克和汤姆静静的坐着，做他们的作业。
