Read the following passage and answer the question.

Trade and commerce

Trade is essentially buying and selling of items produced elsewhere. All the services in retail and wholesale trading or commerce are specifically intended for profit. The towns and cities where all these works take place are known as trading centres.

The rise of trading from barter at the local level to money-exchange of international scale has produced many centres and institutions such as trading centres or collection and distribution points. Trading centres may be divided into rural and urban marketing centres.

Rural marketing centres cater to nearby settlement. These are quasi-urban centres. They serve as trading centres of the most rudimentary type. Here personal and professional services are not well-developed. These form local collecting and distributing centres. Most of these have mandis (wholesale market) and also retailing areas. They are not urban centres per se but are significant centres for making available goods and services which are most frequently demanded by rural folk.

Periodic markets in rural areas are found where there are no regular markets and local periodic markets are organised at different temporal intervals. These may be weekly, biweekly markets from where people form the surrounding areas meet their temporally accumulated demand. These markets are held on specified dates and move form one place to another. The shopkeepers thus, remain busy on all the days while a large area is served by them.

Urban marketing centres have more widely specialised urban services. They provide ordinary Goods and Services as well as many of the specialised Goods and services required by people. Urban centres, therefore, offer manufactured goods as well as many specialised markets develop, e.g. markets for labour, housing, semi or finished products. Services of educational institutions and professionals such as teachers, lawyers, consultants, physicians, dentists and veterinary doctors are available.

Which type of market have no permanent buildings?

Periodic markets