No one knows for sure when advertising first started.It is possible that it grew out of the discovery that some people did certain kinds of work better than others did them.That led to the concept of specialization，which means that people would specialize，or focus，on doing one specific job.
Let’s take a man we’ll call Mr.Fielder，for example.He did everything connected with farming.He planted seeds，tended the fields，and harvested and sold his crops.At the same time，he did many other jobs on the farm.However，he didn’t make the bricks for his house，cut his trees into boards，make the plows(犁)，or any of the other hundreds of things a farm needs.Instead，he got them from people who specialized in doing each of those things.
Suppose there was another man we shall call Mr.Plowright.Using what he knew about farming and working with iron，Mr.Plowright invented a plow that made farming easier.Mr.Plowright did not really like farming himself and wanted to specialize in making really good plows.Perhaps，he thought，other farmers will trade what they grow for one of my plows.
How did Mr.Plowright let people know what he was doing？Why，he advertised，of course.First he opened a shop and then he put up a sign outside the shop to attract customers.That sign may have been no more than a plow carved into a piece of wood and a simple arrow pointing to the shop door.It was probably all the information people needed to find Mr.Plowright and his really good plows.
Many historians believe that the first outdoor signs were used about five thousand years ago.Even before most people could read，they understood such signs.Shopkeepers would carve into stone，clay，or wood symbols for the products they had for sale.
A medium，in advertising talk，is the way you communicate your message.You might say that the first medium used in advertising was signs with symbols.The second medium was audio，or sound，although that term is not used exactly in the way we use it today.Originally，just the human voice and maybe some kind of simple instrument，such as a bell，were used to get people’s attention.
A crier，in the historical sense，is not someone who weeps easily.It is someone，probably a man，with a voice loud enough to be heard over the other noises of a city.In ancient Egypt，shopkeepers might hire such a person to spread the news about their products.Often this earliest form of advertising involved a newly arrived ship loaded with goods.Perhaps the crier described the goods，explained where they came from，and praised their quality.His job was，in other words，not too different from a TV or radio commercial in today’s world.
What probably led to the start of advertising?

A．The discovery of iron.

B．The specialization of labor.

C．The appearance of new jobs.

D．The development of farming techniques.

To advertise his plows，Mr.Plowright ________.

A．praised his plows in public

B．placed a sign outside the shop

C．hung an arrow pointing to the shop

D．showed his products to the customers

The writer makes up the two stories of Mr.Fielder and Mr.Plowright in order to ________.

A．explain the origin of advertising

B．predict the future of advertising

C．expose problems in advertising

D．provide suggestions for advertising

In ancient Egypt，a crier was probably someone who ________.

A．owned a ship

B．had the loudest voice

C．ran a shop selling goods to farmers

D．functioned like today’s TV or radio commercial

The last two paragraphs are mainly about ________.

A．the history of advertising

B．the benefits of advertising

C．the early forms of advertising

D．the basic design of advertising