To their great fear they found in the heaviest snowfall they had ever had.A. they were

问题补充：

To their great fear, they found in the heaviest snowfall they had ever had.

A. they were catching

B. themselves caught

C. they had caught

D. themselves catching

答案：

A. they were catching

(答案→)B. themselves caught

C. they had caught

D. themselves catching

解析：考查find后跟宾补的结构。A、C是宾语从句，they和catch是动宾关系，应该用被动，排除A、C；find sb+doing/ done/adj作宾补，发现某人......。they和catch是动宾关系，排除D。故选B。