The athlete fell off his bike when he down the hill. A. cycledB. was cyclingC. had cycled

问题补充：

The athlete fell off his bike when he down the hill.

A. cycled

B. was cycling

C. had cycled

D. is cycling

答案：

A. cycled

(答案→)B. was cycling

C. had cycled

D. is cycling

解析：考查时态：句意：运动员在朝山下骑车的时候从自行车上掉下来了。因为主句是一般过去式，所以是过去正在做…，用过去进行时，选B。