What do you mean, "Cowhide doesn't blow, train doesn't push"? Used to describe what?

Trains are not driven by manpower, but by their own strength to determine the speed, and cowhide is artificially cut, not blown up.

Ps describes people to seek truth from facts, not to talk big.

Origin:

According to expert research, the word "bragging" originated in the upper reaches of the Yellow River in China.

2. When the Yellow River flows through Qinghai, Gansu, Ningxia, Shaanxi and other provinces (regions), it is difficult to navigate because of the rapids and beaches.

3. In ancient times when the bridge traffic was underdeveloped, people living in the upper reaches of the Yellow River came up with a solution to the problem of crossing the river: using rafts instead of boats.

4. Before 1950s, kayaking was always an important means of transportation for people living in the upper reaches of the Yellow River, where the railway had not been opened and the road traffic was inconvenient.

Canoeing exercises are roughly as follows:

1. When slaughtering, first try to peel off all the fur of sheep or cattle, then depilate all the fur with salt water, then coat vegetable oil on its limbs and neck, soak it in water, expose it to the sun to soften it, then sew it into a bag with a string, leaving only a small hole, blow it fully, then seal the small hole, and then tie several leather bags together with wooden boards to make a raft.

In ancient times, people didn't have a pump and an air pump, so there was only one way to inflate a raft-blowing it with your mouth. The sheepskin bag is small in size and can be blown directly with the mouth. But even sheepskin bags can only be blown up by people with very strong physique and large lung capacity.

Because the cowhide bag is too big, you can't blow it directly with your mouth. Therefore, in the upper reaches of the Yellow River, if someone says that he can blow cowhide bags, it will be considered as bragging;

When the residents there are impatient with others' bragging, they often say to them, "Go to the Yellow River to brag if you dare!" Over time, "boasting" gradually became synonymous with "boasting" and gradually spread.