I have been wearing zipper pants for more than ten years. I just learned this little common sense...

On Tuesday, I went to buy a pair of jeans. I was in a rush to get a car and tried it in the fitting room. I felt like the zipper was easy to slide, then I asked the waiter. "Why is the zipper of many trousers easy to slide now? It feels like a zipper is too loose. Is there a tight Zip ?", The waiter said no, it was very tight. Then he took one and looked at it. After trying a few times, he said it was a little easy to decline. After pulling a few times, she suddenly got stuck and failed to slide. Then she was excited that she had finished pulling the zipper and pressed it down. If she got stuck, it would not go down, this is what she just discovered !! I tried it quickly. It turned out to be true! Then I bought it and changed the old trousers. I tried it and found that this trousers also has this function! But I have been wearing it for so long, and I never found out that he used to have this function. Khan !! In the past, it was a timed check, and he always fell down! Later, I asked my colleagues and friends. They all know that !! Maybe many people do not know this common sense, because they often see that their zipper is on, or that the pants do not have that function ??