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

As it involves only a small ___ , we hope you will have no difficulty on promotion.( )

Will you send us _____ return mail pamphlets and price list ____ your exports?

____ your in formati on, we have received a crowd of enq uiries from buyers in other directi on s.( )

Scientists doubt wheth er it ’s ________ to regulate one ’s biological clock by drinking.