On March 14, maths and science lovers around the world celebrated a special day: Pi Day.

    Pi is{#blank#}1{#/blank#} to3. 14, but the number goes on endlessly. It is sometimes written in Greek,π. With the help of computers, mathematicians have been able to {#blank#}2{#/blank#} pi out to over trillion (万亿) decimal places, but there is still no{#blank#}3{#/blank#} to the number. This makes pi puzzling, even for the most famous scientists and mathematicians.

    Pi Day is celebrated around the world on March 14, since how we write this date, 3/14,looks just like the number pi.

    For some people, the appeal (吸引力) of Pi Day goes far beyond maths and science. Pi shows up{#blank#}4{#/blank#}popular culture. You can see it in movies, comics, music and more. "In modern movies, any time the filmmaker wants to evoke (产生) a sense of mystery, often the symbol pi is used, "says David Blatner, Jewish American writer of The Joy of Pi.

—It's {#blank#}1{#/blank#} your grandparents room, {#blank#}2{#/blank#}the wall. (on/in)