The policeman, for his bravery, is going to give us a speech tomorrow.
A. to know
B. known
C. having known
D. knowing
网友回答
A. to know
(答案→)B. known
C. having known
D. knowing
解析：句意:那位出名的警察将明天给我们作一次演讲。这里整个句子已经有谓语动词，所以空格处只能用非谓语动词，policeman与know之间是动宾关系，应该用过去分词，故选B。