Merchant uses cards to promote services in order to induce users to use them.

The "baby-walking artifact" is actually a children's stroller. Because its structure is very simple, it is very convenient to use.

There are many models on the market with 3 wheels. Normally, there will be no problem when the stroller passes on a flat road. However, if it goes downhill or passes on uneven roads, the direction control of the stroller may be affected.