Whether it is a workman or an executive, earphones have become an (1)______ part of our lives, sometimes even leading to tragicomic situations. The other day, an electrician had come to our house to (2)__________ something. We told him in (3)_____ what needed to be done. But after he left, I found that the man had done almost nothing. It later turned out that he could not hear our (4)_______ clearly because he had his earphones on.