阅读理解。

阅读下面短文，从每题所给的A、B、C、D四个选项中，选出最佳选项。

　　The pig was the last animal to be domesticated(驯养) by the farmer．Unlike the cow and the sheep, it is not a grass eater. Its ancient home was the forest, where it searched for different kinds of food, such as nuts, roots and dead animals, and found in the bushes protection for its almost hairless body from extremes of sun and cold. For many centuries the farmer allowed it to continue there, leaving his pigs to look after themselves most of the time. As the woodlands began to become smaller, the pig slowly began to be kept on the farm itself．But it did not finally come into a shed, where it was fed on waste food from the farm and the house, until the eighteenth century.

　　The pig, then became a farm animal in the age of agricultural improvement in Britain in the eighteenth century, but it was given little attention by special animal breeder(饲养者), for the major farmers of the time preferred to develop the larger kinds of animals. There were, however, various less well-known farmers interested in pigs and they based their improvements on new types of pigs from overseas. These were the Chinese pigs, and their various relatives, including the Neapolitan(那不勒斯) pigs, which were descended(后代) from Chinese pigs that had found their way to Mediterranean in ancient time. These were very different from the thin and leggy British woodland pigs. They were wider and squarer, with shorter legs and flatter faces, and they matured(成熟) earlier and produced more delicate meat(精瘦肉). By the end of the eighteenth century these overseas pigs had influenced(影响) the color, shape of the native British pigs a great deal.

　　In the early nineteenth century, pig farmers worked at improving all sorts and conditions of pigs. Many of the special pigs they developed are now forgotten, but by the end of the century they had developed most of the kinds we know in Britain today.

1．In their original wild stage pigs ________.

[　　]

A．were grass eaters

B．ate the same food as other animals

C．lived among trees

D．went about in the plains

2．Until the 18th century pigs were not fully domesticated in Britain, because ________.

[　　]

A．they could find food for themselves well enough in woodlands

B．they did not grow well when kept indoors

C．there was no suitable food for them on most farms

D．it was difficult to develop improved types of pig

3．How did Chinese and Neapolitan pigs differ from native British pigs?

[　　]

A．They were taller.

B．They were rounder.

C．They had stronger legs.

D．They had shorter noses.

4．What conclusion may be drawn from the passage?

[　　]

A．The British farmers settled new kinds of pigs.

B．A new type of pig produced more delicate meat.

C．The Chinese pigs were well bred at that time.

D．The British farmers improved the breed of their native pigs in the 18th century.