问题补充：
The poor boy seems the news that his father died in the car accident for there is no sign of sorrow on his face.
A. not to be known
B. not to have received
C. to have not received
D. not to know
答案：
A. not to be known
(答案→)B. not to have received
C. to have not received
D. not to know
解析：考查不定式的用法：句意：可怜的男孩似乎不知道他父亲去世的消息，因为在他的脸上看不见悲伤的表情。Seem后面接不定式做宾语，seem to do似乎要做…，seem to be doing似乎正在做…，seem to have done似乎已经做…，否定词not放在to前面，根据句意选B.
