US Census

    An old man was sitting on his porch （门廊）, when a young man walked up with a pad and pencil in his hand.
    "What are you selling young man," the oldman asked.
    "I'm not selling anything," the young man said. I'm the Census¹ Taker(户口调查人员）.""A what?" the old man asked.
    "A Census Taker. We are trying to find out how many people are in the United States.""Well," the old man answered, "you're wasting your time with me, I have no idea."

1 census   

n.(官方的)人口调查，人口普查

参考例句：

• A census of population is taken every ten years.人口普查每10年进行一次。
• The census is taken one time every four years in our country.我国每四年一次人口普查。