剑桥雅思19听力test1section4原文答案解析+文本精讲（第31题到第40题）

[01:27.16]For my presentation today, I'm going to talk about the Céide Fields in the northwest of Ireland, one of the largest Neolithic sites in the world.
[01:39.75]I recently visited this site and observed the work that is currently being done by a team of archaeologists there.
[01:47.16]The site was first discovered in the 1930s by a local teacher, Patrick Caulfield.
[01:53.85]He noticed that when local people were digging in the bog, they were constantly hitting against what seemed to be rows of stones.
[02:02.90]He realised that these must be walls and that they must be thousands of years old for them to predate the bog which subsequently grew over them.
[02:12.94]He wrote to the National Museum in Dublin to ask them to investigate, but no one took
him seriously.
[02:19.85]It wasn't until 40 years later, when Patrick Caulfield’s son Seamus, who had become an archaeologist by then, began to explore further.
[02:30.45]He inserted iron probes into the
bog to map the formation of the stones, a traditional method which local people had always
used for finding fuel buried in the bog for thousands of years.
[02:43.95]Carbon dating later proved that
the site was over 5,000 years old and was the largest Neolithic site in Ireland.
[02:54.15]Thanks to the bog which covers the area, the remains of the settlement at Céide Fields, which is over 5,000 years old, are extremely well-preserved.
[03:05.64]A bog is 90 percent water;
[03:08.44]its soil
is so saturated that when the grasses and heathers that grow on its surface die, they don't
fully decay but accumulate in layers.
[03:19.43]Objects remain so well preserved in these conditions because of the acidity of the peat and the deficiency of oxygen.
[03:27.08]At least 175 days of rain a
year are required for this to happen;
[03:33.24]this part of Ireland gets an average of 225 days.
[03:43.19]The Neolithic farmers at Céide would have enjoyed several centuries of relative peace and
stability.
[03:50.15]Neolithic farmers generally lived in larger communities than their predecessors,
with a number of houses built around a community building.
[03:59.13]As they lived in permanent
settlements, Neolithic farmers were able to build bigger houses.
[04:05.81]These weren't round as people often assume, but rectangular with a small hole in the roof that allowed smoke to escape.
[04:14.87]This is one of many innovations and indicates that the Neolithic farmers were the
first people to cook indoors.
[04:23.19]Another new technology that Neolithic settlers brought to Ireland
was pottery.
[04:28.49]Fragments of Neolithic pots have been found in Céide and elsewhere in Ireland.

[04:34.21]The pots were used for many things; as well as for storing food, pots were filed with a small
amount of fat and when this was set alight they served as lamps.
[04:46.03]It's thought that the Céide Fields were mainly used as paddocks for animals to graze in.

[04:52.89]Evidence from the Céide Fields suggests that each plot of land sustain an extended family.
[05:00.86]They may have used a system of rotational grazing in order to prevent over – grazing and to allow for plant recovery and regrowth.
[05:10.53]This must have been a year - round activity as no structures have been found which would have been used to shelter animals in the winter.
[05:18.18]However archaeologists believe that this way of life at Céide ceased abruptly. Why was this?

[05:27.33]Well, several factors may have contributed to the changing circumstances.
[05:32.10]The soil would have become less productive and led to the abandonment of farming.
[05:37.30]The crop rotation
system was partly responsible for this as it would have been very intensive and was not
sustainable.
[05:45.16]But there were also climatic pressures too.
[05:48.22]The farmers at Ceide would have
enjoyed a relatively dry period, but this began to change and the conditions became wetter as
there was a lot more rain.
[05:58.47]It was these conditions that encouraged the bog to form over the area which survives today.
[06:05.49]So now I’d like to show you some ...