Add since or for :
-I've waited here [?] five o'clock
-I've written letters [?] the last two hours
-She hasn't worn that dress [?] two years
-I have read two novels [?] yesterday
-We have studied English [?] only six months
-How long has that fire been burning? [?] last night
-Coal has got clearer [?] last year
-Have you seen John lately? Not [?] three or four days
-I have written four letters [?] breakfast
-I'm sure that boy hasn't washed his face [?] yesterday
-Have you visited your uncle recently? Not [?] last Monday
-I have stood here [?] half an hour, but the bus hasn't come yet
-How many words have you learnt [?] our last lesson
-We have sat on these hard seats [?] nearly an hour
-How often have you spoken to him recently? Twice [?] last week
-She's been in London [?] Monday
-Mike has been ill [?] a long time.He's been in hospital [?] October
-My aunt has lived in Australia [?] 15 years
-Nobody lives in those houses. They have been empty [?] many years
-Mrs. Harris is in his office. She's been there [?] 7 o'clock
-India has been an independent country since 1947
-The bus is late. We've been waiting [?] 20 minutes