阅读判断。根据短文内容，判断下列句子的正与误。

Long long ago, there was no paper in the world. People had to write characters(汉字) in bamboo slips or stones.Then there was a man named Cai Lun who was a Chinese man. He made people use all kinds of things to invent paper. From then on, people can use paper to write on. Paper is a great invention. We always remember the great inventor Cai Lun. Nowadays paper is very useful in our work, study and our life.It really means a lot to human beings

下列英雄模范人物，不属于十年建设时期的是（   ）

围成一个图形的所有边长的总和叫做这个图形的____。

一个正方形的边长是12厘米，它的周长是____厘米。