Tom concluded his lecture that he couldn’t emphasize enough how important our efforts wer

问题补充：

Tom concluded his lecture that he couldn’t emphasize enough how important our efforts were.

A. to say

B. saying

C. said

D. having said

答案：

A. to say

(答案→)B. saying

C. said

D. having said

解析：考查非谓语动词。根据句子结构可知可知此处saying做状语，say与逻辑主语之间是主动关系，故选择saying。