How to fasten the strap of the schoolbag?

The binding method of schoolbags is as follows:

1, backpack shoulder strap method: firstly, buckle the shoulder strap of the schoolbag in three places: A, B and C, and put it in from A and out from B. At this time, the length of the shoulder strap can be adjusted, or it can be adjusted after putting it on. Then come out from C, so that the shoulder strap forms a ring. Leave a space between A and B, put the shoulder strap in from B, put it out from A, and then tighten it. Then, the lower shoulder strap is also tightened, thus forming a very strong shoulder strap for the schoolbag, and even the schoolbag with a heavy back will not slide down.

2, the shoulder strap method of one-shoulder backpack: find the bag with buttons, it is usually an object similar to Japanese characters, with upper and lower squares. Pass the adhesive tape upward from the lower box and outward from the upper box. Fasten the strap from the front, and then fasten it from the lower cabin. Then adjust the length of the belt slightly to make it neither too tight nor too loose, which is suitable for the figure. Make sure that the straps on both sides are the same length, so that you won't be askew when you carry them. At this time, the shoulder strap of the one-shoulder backpack is fastened.