We have received your letter of September 12，（）we are glad to know that you are interested in our electric heaters. which。 atwhich。 fromwhich。 inwhich。
We are（）to have your enquiry for Sewing Machines. please。 pleased。 pleasure。 in pleasure。
We have to point out that the post ponement of the fulfilment of the contract（）caused us certain expenses. had。 have。 has。 having。
We（）the seminar sponsored by you in September last year. aware。 aware of。 are aware of。 are aware。
We（）if you could give us whatever information you can in this respect. should appreciate。 appreciate。 appreciate it。 should appreciate it。
We shall do everything possible to assist you in（）a mutually beneficial trade.
