I often go to school every day.A. by busB. by a busC. by the busD. on bus

问题补充：

I often go to school every day.

A. by bus

B. by a bus

C. by the bus

D. on bus

答案：

(答案→)A. by bus

B. by a bus

C. by the bus

D. on bus

解析：句意：我每天经常乘公共汽车去上学。by bus 是固定短语，乘坐公共汽车，其中不需要用任何冠词。故选A。