【简答题】The letters in this text are 1 letters, with 2 expressions and 3 , contracted 4 forms and 5 6 , and the 7 of informal letters are also different from that of formal ones.
【简答题】The letters in this text are 1 letters, with 2 expressions and 3 , contracted 4 forms and sentence 5 , and the 6 of informal letters are also different from that of formal ones.