Did you hear__knock at the door?-No,I__to my MP3.

Did you hear anybody knock at the door?No ,I ____ to my MP3 Did you hear someone knock at the door Did you tell your brother the good news at that time?No,my m no cover at the door ______ at the door before you enter my room,please. "Did you heard someone knocking at the door?"为什么要用at? Did you hear someone[ ] 【knock】 at the door when you[ ]【 wat Did you lock the door?—No,I ____,but I forgot.A.should B.mus you did lock the door,I suppose? what did you get () your birthday?An MP3,from my aunt A at B Would you mind ___ the door?No not at all.Go ahead.A.open B. -_ did you live at the time?-At No.3,Beijing Road.