（1）The following items totaling $4000 are still open on your account.
你的欠款總計為4000美元。
（2）It is now several weeks since we sent you our first invoice and we have not yet received your payment.
我們的第一份發票已經寄出有好幾周了，但我們尚未收到你的任何款項。
（3）I'm wondering about your plans for paying your account which,as you know,is now over 40 days ast due.
我想了解一下你的.付款計劃，要知道，你的付款已經逾期40多天了。
（4）We must now ask you to settle this account within the next few days.
請你務必在這幾日內結清這筆賬款。