Fill in the blanks with appropriate prepositions. Dear Sirs, We _1_ received and checked your statement _2_ the quarter ended January 27 and agree with the balance of $7,780 shown to _3_ due. Up to now we have _4_ no difficulty _5_ meeting our commitments and have always _6_ our accounts _7_ you promptly. We could _8_ done so now, but for the bankruptcy of _9_ important customer, _10_ affairs _11_ not likely to _12_ settled for some time. We should therefore _13_ most grateful _14_ you would _15_ us to defer payment of your present account _16_ the end of April. During the next few weeks, we shall be _17_ payments under a number of large contracts and if you grant our _18_ , we shall _19_ no difficulty in settling with you _20_ full when the time comes. Yours sincerely.