As he reached front door Jack saw strange sight.A. the; aB. a; aC. the; /D. / ；a

问题补充：

As he reached front door, Jack saw strange sight.

A. the; a

B. a; a

C. the; /

D. / ；a

答案：

(答案→)A. the; a

B. a; a

C. the; /

D. / ；a

解析：句意：当他到达前门的时候，杰克看见了令人吃惊的一幕。这里第一空必须特指的前门，第二空表示泛指令人吃惊的一幕，故选A。