The boy seated himself in the corner with his back to his father.
A. turning
B. to turn
C. to be turned
D. turned
网友回答
A. turning
B. to turn
C. to be turned
(答案→)D. turned
解析：考查非谓语动词。turned to his back在这里是过去分词短语作宾语补足语, 表状况turn和前面的宾语 his back 为被动关系, 故用过去分词。句意：男孩坐在角落里，背对着他父亲。故D正确。