Jack usually goes to school by bike today he walked to school.A. andB. butC. orD. so

问题补充：

Jack usually goes to school by bike, today he walked to school.

A. and

B. but

C. or

D. so

答案：

A. and

(答案→)B. but

C. or

D. so

解析：and和，并且；but但是，可是；or或者，是否； so因为。句意：杰克通常骑自行车去学校，但是今天他步行去了学校。结合语境可知选B.