.（2010·浙江温州中学高三9月月考）      10. ---What did you hear last night?

--- I seemed ______ someone knock at the door.

A. to have heard        B. to be heard       

C. to be hearing         D. having heard

从所给的四个选项中选择最佳答案

—What did you hear last night?

—I seemed ______ someone knock at the door．　　　

[　　]

A．hear　　　B．to have heard　　　C．to hear　　　D．being heard