One should always ________ his promise.

One should always ________ his promise.

A.stick to

B.insist on

C.persist in

D.keep to

答案及解析： A

考查词组的含义。stick to表坚持（原则、计划、诺言、决定、意见等）．insist on表坚持（意见．主张）．persist in表示坚持行动，有时表固执己见或坚持不改。