That teacher can elaborate on the process of making air models, that is, water amusement balls, inflatable toys, inflatable bathtubs and the like, and what materials and tools are used.

A few days before I left Shanghai, I bought a 4-meter *5-meter inflatable sand pool ... When I came back to inflate it, I found that only four corners touched the ground, and the middle part was arched. The arch positions are all 25 cm above the ground ... the size is not right ... the air leakage is also very serious ... After filling it up, there is no air for 1-2 hours ... Supplementary question?

Let's take a look at the fact of the camber of this bed first.