He gets to school.A. ride a bikeB. by a busC. take a trainD. on foot

问题补充：

He gets to school.

A. ride a bike

B. by a bus

C. take a train

D. on foot

答案：

A. ride a bike

B. by a bus

C. take a train

(答案→)D. on foot

解析：by在表示交通方式时，后面直接接交通工具。on表示在交通工具上面；ride是动词，骑。句意：他步行去学校。结合语境可知本句不缺少谓语动词，选项B结构有误，故选D。