通读下面的短文，掌握其大意。然后，从每小题的四个选择项中选出可填入相应空白处的最佳选项。

     Recently, some scientists decided to find out what the funniest joke in the world was. This was clearly a(an)  task, as no two people ever really agree about what is funny and what is not—  when they are from different . 

     Telling jokes is something people often  around the world. , jokes are sometimes not funny or are often not  by people who are not part of that culture (文化).
     Anyhow,  a year-long serious study, the scientists  the funniest joke in the world:
     Two hunters (猎人) are out in the woods. One of them  to the ground. He doesn’t seem to be , his eyes closed. The other hunter takes out his phone and calls emergency (紧急) services. “My friend is dead!” he  to the man on the other side, “What can I do?” The man, in a(an)  voice, says, “Don’t worry. I can . First, make sure he’s .” There is a silence, then a shot is . Bang! The hunter’s voice comes back on the line. He says, “OK, now what?"