默认:clip: auto;
clip: rect(0px, 100px, 200px, 0px);
clip: rect(0px, 200px, 200px, 100px);
clip: rect(0px, 200px, 100px, 0px);
clip: rect(100px, 200px, 200px, 0px);
clip: rect(0px, 100px, 100px, 0px);
clip: rect(0px, 200px, 100px, 100px);
clip: rect(100px, 200px, 200px, 100px);
clip: rect(100px, 100px, 200px, 0px);