65438+ done.
2. The second type of cross-wrapping requires that the shoelaces should not be too thick to avoid inserting the same hole twice. Shoelaces should be inserted from the top of the bottom two holes respectively, and the shoelaces should be exposed to the same length, then go out from the inside of the second hole, then go through the first hole from the outside, then cross, then go through the third hole from the inside, then go through the second hole again from the outside, and then cross.
3. The third two-color mixed system needs two shoelaces of different colors this time. Put two shoelaces through the hole on the first floor from the inside, and then make a summary of the two shoelaces left inside. The smaller the knot, the more you can avoid exposure. Pull out the two shoelaces on the outer side, then cross them, adjust the intersection point to the center of the shoe, then respectively pass through the holes on the second layer, then cross them out from the holes on the third layer again, and repeat the third step.