问题补充:
--- Do you often ride bike to school, Tom?
--- No. I usually come to school by bus.
A. a, a
B. a, the
C. /, /
D. a, /
答案:
A. a, a
B. a, the
C. /, /
(答案→)D. a, /
解析:句意:你经常骑自行车去学校吗?汤姆。——不,我通常成公交车来学校。结合语境可知上文指的是骑任何一辆自行车,故用不定冠词。下文by在表示交通方式时,后面直接接交通工具,故选D。