We should be pleased to send you any of our typewriters on appro

We should be pleased to send you any of our typewriters on approval _______ our own expense.
A、at
B、for
C、on
D、in
【正确答案】：A
【题目解析】：at our own expense 自费。句意：我们乐意寄给你试用的打字机，费用由我们自己承担。