题目

   There are some famous buildings in the world. Everyone can recognize（认出）them with their imaginations. For example, when you see a picture of a sports stadium（体育场）that reminds you of a bird’s nest, you probably know it is the Olympic stadium in Beijing.    In fact, other buildings can be recognized more easily. The shape of the building shows the objects people can see inside. In Guizhou, China, people can visit the Meitan Tea Museum, built in the shape of a big teapot. From far away, the teapot-shaped museum looks like some kind of huge work of art. But as one 下列说法不正确的是 [　　] A．有一个角是直角的菱形是正方形 B．两条对角线相等的菱形是正方形 C．对角线互相垂直的矩形是正方形 D．四条边都相等的四边形是正方形