Thebasicunitinthestudyofmorphologyis______.
Wetrustyouwilldoyourbesttohavethismatter__________rightaway.()
Ourpaymentterms(付款方式)are___,irrevocableletterofcreditforthefullinvoicevalue.()
Theoldcouplehavebeenmarriedfor40yearsandneveronce_______witheachother.
MarkTwainemployedanunpretentiousstyleof()inhisnovelswhichisbestdescribedas“vernacular”.