OneSundayMarkdecided的精选

问题详情：缺词填空;根据短文内容及首字母提示写出所缺单词。OneSunday,Markdecidedtogosailing(航海)inhisboatwithhisfriendDan,butDanhappenedtobeaway.Dan'sbrotherJohnofferedtogoi____1___thoughhedidnotknowany...