题目内容:
We regret ______ to accept your terms of payment and therefore have to return the order to you.
A、cannotB、beingunable
C、notable
D、notbeable
参考答案:【答案仅供学习,请勿对照自行用药等】
We regret ______ to accept your terms of payment and therefore have to return the order to you.
A、cannot