A、Not later than Sept. 20. B、15 to 20 days before delivery. C、15 days after shipment. D、A week before shipment. B根据原文可知，付款方式为信用证

M: Good morning, Mrs. Black. Any news?
W: Good morning, Mr. Brown. Yes. I’ve succeeded in persuading (说服，使相信) our export manager to agree to reduce the price by ten percent. He made this an exception with an eye to future business.
M: Great! We certainly appreciate that.
W: OK. 15 Tunnel Drillers at 57600 Swiss Francs each, FOB European Main Ports, is that right? Business is closed at this price.
M: Yes, right. Shall we go over the other terms and conditions of the transaction?
W: All right. We have no objection to the stipulations (条款，约定的条件) about the packing and shipping marks.
M: The machines must be well protected against dampness, moisture (水分，湿气), rust, and be able to stand shock and rough handling.
W: We’ll see to that.
M: They are to be shipped not later than September 20.
W: There’s no question about that.
M: And what about the terms of payment?
W: Payment by the letter of credit, to be opened by the buyer 15 to 20 days prior to the date of delivery. That’s what we have agreed upon, isn’t it?
M: Yes, quite so.
W: We’d like to add the condition that letter of credit shall be valid until the 15th day after shipment. You know, it sometimes takes us a week or so to get all the shipping documents ready for the presentation and negotiation. This will give us more leeway (自主权).
M: That can be done. Any questions about the inspection and claims?
W: No. The quality and performance of our machines can stand every possible Test. We agree to your conditions.
M: Do you also agree to the condition that all disputes, if unsettled, shall be referred to the Foreign Trade Arbitration Commission for the Promotion of International Trade?
W: Certainly, but I’m sure there will be no occasion for arbitration (仲裁).
M: Well, then, we’ve agreed on all the major points.
W: Yes, Mr. Brown. We’re glad the deal has come off nicely. When can the contract be ready for signature?
M: I’ll have it ready in a couple of days.
W: The earlier the better. I’m leaving next week.
M: How about next Monday afternoon at 5? I’ll have a copy of the contract sent to your hotel in the morning for you to look over.
W: That suits us fine. Then, goodbye.
M: Goodbye, Mrs. Black.
1. What did the export manager agree to do?
2. What price do they agree about one driller in the conversation?
3. Which is NOT their agreement on packing and shipping of the machines?
4. When will the letter of credit be opened?
5. What may be the woman’s feeling about this business discussion?