My brother to the ground while his bicycle and hurt his leg .Afalls; is he ridingB

问题补充：

My brother to the ground while his bicycle and hurt his leg .

Afalls; is he riding

Bfell; he was riding

Cfall; he is riding

Dfelt; was he riding

答案：

A. falls; is he riding

(答案→)B. fell; he was riding

C. fall; he is riding

D. felt; was he riding

解析：句意：我哥哥骑自行车时摔到地上摔伤了腿。while后跟过去进行时，此处主句用过去时，fall的过去式是fell，故选B。