I will buy you a new bike if you learn how to swim this summer.Is that a ? I’m sure I’ll

问题补充：

I will buy you a new bike if you learn how to swim this summer.

Is that a ? I’m sure I’ll get the bike.

A. chance

B. promise

C. trick

D. treat

答案：

A. chance

(答案→)B. promise

C. trick

D. treat

解析：Chance是机会；promise是承诺；trick是把戏窍门；treat是治疗，款待。句意：今年夏天，如果你学会了如何游泳，我就给你买一辆新的自行车。——那是一个承诺吗？我敢肯定我能得到自行车。结合语境可知选B。