When I entered the room, I found a little boy on his mother’s knees to draw a picture.
A. seated; learning
B. sitting; to learn
C. seating; learning
D. sat; was learning
网友回答
(答案→)A. seated; learning
B. sitting; to learn
C. seating; learning
D. sat; was learning
解析：seat是及物动词，后没有宾语， 故此处用过去分词做后置定语 表示“坐在……”a little boy 是learn的执行者所以用learning。