1. See the individual, find symmetry, fold and overlap along the axis, and rotate the center as well. 2. There is no symmetry. If you want to close, don't forget to form an angle and count closed surfaces. 3. If you don't turn it off, you must turn it on. Whether you open it or close it, you will find the same rule. 4. The same straight, total bending, straight bending respectively, see two lines alternating. 5. One stroke, which is also common, must be excluded, and the path is not repeated. 6. the same group of drawings, multi-faceted, ask what characteristics, and judge the options.