Mongolians prefer the name ger because 'yurt' was the word used by invaders from the West.

Although they can be easily folded to fit on the back of a horse and set up in half an hour - just like a tent - a ger is more than a tent.

They are designed for long-term habitation and to keep their inhabitants warm in winter and cool in summer.

A basic ger is made out of wood and felt.

The wood is used to make lattice walls, the door and the roof and the interior.

Felt or animal hides are then wrapped around the wooden structure and secured with rope. The covering materials can be made of human or animal hair.

The interior of the ger may be decorated with rugs and would include everyday utensils for shepherding and weaving.

Gers are set up when new pastures are found for herds, although in modern-day Mongolia they may only be used as showpieces for visitors.

Which is the most expensive painting in the world?

The world's most expensive painting is Portrait of Dr Gachet by Vincent Van Gogh.

Van Gogh also painted Sunflowers and many other priceless paintings.

Portrait of Dr Gachet is a picture of Van Gogh's doctor and was sold by Christie's in New York to Japa nese businessman Ryoei Saito for US$82.5 million (HK$643 million) on May 15, 1990.

As Van Gogh neared the end of his life, he became a little mad and was often admitted to a mental asylum.

It was during one of these stays that he painted the picture of his doctor.

Immediately after purchasing it, the businessman threatened to burn it when he died, to stop his heirs from having to pay a huge inheritance tax.

He died six years later, and no one has since seen the painting. So did he really burn the painting before he died? We may never know.

What is meant by the term 'division of labour'?

Division of labour is the separation of a work process into a number of tasks.

Each task is done by a separate person or group. It is most often used in mass-production systems.

An example is the motor car industry which employs thousands of people. Each employee only knows how to make a small part of a car.

Breaking down work into simple, tasks cuts out unnecessary motion and limits the handling of tools and parts. This in turn lowers production costs and makes for a less expensive final product.