whydon'tandcouldn'timakeamistakeinreferencetoyouraddress,iwonder?
Idon’tknowwhyImadesuchawfulblunderofhisaddress;butasitwassafelyreceived,itisalright.Iattributedmyblundertomynon-infallibilityandyouarecompelledtopardonmethistimeatleast.Whydon’tandcouldn’tImakeamistakeinreferencetoyouraddress,Iwonder?
这段是全段,怎么don'tandcouldn't?