As he reached front door Jack saw strange sight.A. the; 不填B. a; theC. 不填aD. the; a

问题补充：

As he reached front door, Jack saw strange sight.

A. the; 不填

B. a; the

C. 不填a

D. the; a

答案：

A. the; 不填

B. a; the

C. 不填a

(答案→)D. the; a

解析：第一空特指前门，故用定冠词the，第二空是指一种奇怪的景象。故用不定冠词ａ．句意：当他到达前门时，杰克看到一种奇怪的景象。