Results for unavoidable translation from Tamil to English

dear sir,i had obtained a demand draft (dd no: -----) on ------ (date) from your bank for rs. -----/- in favor of ----- (the person for whom you took the dd). due to some unavoidable circumstances, this dd is no longer required. hence i request you to cancel the dd and deposit the money into my savings account no: ----- (your account number)thanks,your signature.address the letter to the bank manager and you would get the dd cancelled and money deposited to your account.
in infectious diseases epidemiologe, vector is defined as an arthropod or any living carrier[e.g;snail]that transports an infectious agent to asusceptible individual.transmission by a vector may be mechanical or biological. in the letter case, the disease agent passes through a develomental cycle or mulitiplication in the vector