We regret ______ to accept your terms of payment and therefore have to return the order to you.

We are glad to receive your telegraphic order of May 6, ______ regret that we can not supply the goods ______ the end of May.

We are pleased to say that we are ______ to supply you ______ the goods you want.

Welookforwardto____trialorder.

We have received your letter of September 12, ______ we are glad to know that you are interested in our electric heaters.