13. We would also accept a certified check as well as a direct bank remittance.
我們也接受保付支票或是銀行直接匯款。
還能這樣說：
Either certified check or direct bank remittance is all right.
We accept payment by certified check or direct bank remittance.
應用解析：
powerful check to sth. 對……有力的控制；
under proper checks and restraints 在適當的控制之下；
suffer a check 受挫

14. Payment might be refused if anything goes wrong with the documents.
如果單據有問題，可以提出拒付。
還能這樣說：
We approve of refusal of payment if anything goes wrong with the documents.
Under the circumstance that the documents go wrong, we will allow the buyers refuse to pay.
諺語：
Losers are always in the wrong.
勝者為王，敗者為寇。

15. It would help me greatly if you would accept D/P.
你如果能接受付款交單的話，會對我有很大幫助。
還能這樣說：
It would be greatly helpful if you would accept D/P.
It would benefit greatly if in case that you accept D/P.
應用解析：
accept sb.'s good will 接受某人的好意；
accept sb.'s hand in marriage 答應與某人結婚；
accept sb.'s reasons 相信某人的理由

16. Payment is to be made before the end of this week.
這個周末以前應該付款。
還能這樣說：
You have to pay before the end of this week.
The deadline of the payment is this weekend.
應用解析：
this day week 一星期后的今天；
week after week 一個星期接另一個星期，一連數周；
week in week out 每個星期都，毫無例外；
every other week 每隔一周

17. We may have some difficulties making payment in pound sterling.
用英鎊付款可能會有困難。
還能這樣說：
It may be difficult to pay by pound sterling.
We have trouble to choose pound sterling as the means of payment.
應用解析：
make a difficulty 刁難，找麻煩；
iron out difficulties 除去障礙，使事情圓滿