They decided to go to school____instead of walking there.hey decided to go to school____instead of walking there.A.by bikes B.on foot C.by train

A
后面是 walking 自然不能选 B
C 更离谱，你见过有人上学天天做火车的吗
但是 A 也不妥当，应该是 by bike
相较而言，还是选 A

They decided to go to school_C___instead of walking there.
A.by bikes B.on foot C.by train

C

b

C
由instead of walking there知,B是不对的,而A若改为by bike就对了

C.by train
on foot 和walk矛盾
by bikes 中bike不加s

B