高等继续教育 / 经贸英语
正确率:100%
题型描述: 单选题
_ _ _ _ _ you accept our offer, please cable us for our confirmation.
A.unless
B.as
C.if
D.until
_ _ _ _ _ you accept our offer, please cable us for our confirmation.
A.unless
B.as
C.if
D.until
参考答案: