We wih to acknowledge receipt of your letter of March 15,（）reached us yesterday.

Your immediate reply should reach us not later（）the end of this month.

We shall book a trial order with you,（）goods are competitive in price and of good quality.

We are glad to enter （） business relations with your corporation.

We trust the mentioned shipment will reach you（）sound condition.

We have established an irrevocable letter of credit（）your favour with the Bank of China,Guandong．

While （） an enquiry, you ought to enquire into quality specification and price etc.

We hope that you wil look（）the cause of the defective goods.

As to chemical products we are well connected（）the major producers in America.

Please take the necessary steps（）delay.