At present, most people in cities tend to buy most of their weekly food and household items on a certain day of a week, but it is quite labor-consuming due to numerous articles purchased during shopping as well as the need to carry the articles to their cars. 
Consequently, shopping carts are available for customers in almost all supermarkets.  However, the whole process, from borrowing a shopping cart, transporting the articles to their cars, returning the shopping cart, to transferring the articles from the cars to kitchens when arriving home, is tedious, inefficient and quite labor-consuming.  Particularly for the elderly and infirm, it is difficult to complete this task.  Meanwhile, it is not environmentally friendly to use a lot of plastic bags.