题目

For centuries, people wondered how big the Earth was. Unfortunately, although the Earth was flat, no one was able to figure out its size. Gradually, however, people began to realize that the Earth was really round.Then, in the third century BC(2,300 years ago), a Greek man named Eratosthenes had an idea. Eratosthenes was sure that the Earth was a sphere. He used the sun and geometry(几何学) to figure out the size of the Earth. He calculated that the circumference(圆周) of the Earth was 28,600 miles(46,000 kilometers). The true size of the Earth is 25,000 miles(40,000 kilometers).Eratosthe17．Neither you nor anybody else        content to live in such a lonely village．（　　）A．isB．amC．areD．were