问题 问答题 简答题

简述基底胶结和孔隙胶结的基本特点。

答案

参考答案:

基底胶结

①颗粒之间不互相接触。

②颗粒悬浮于胶结物(杂基)之中。

③代表着密度较大的水流快速规程的特征。

④填隙物含量多,成分主要为粘土物质。

孔隙胶结

①颗粒之间多呈点状接触。

②填隙物主要分布于颗粒之间孔隙中。

③反映了稳定水流沉积作用和波浪淘洗作用的特征。

④填隙物可以是粘土杂基,也可以是化学胶结物。

单项选择题
阅读理解

阅读理解。

     Have you winterized your horse yet? Even though global warming may have made our climate more

mild,many animals are still hibernating(冬眠). It's too bad that humans can't hibernate.In fact, as a

species, we almost did.

     Apparently, at times in the past, peasants in France liked a semistate of human hibernation.So writes

Graham Robb, a British scholar who has studied the sleeping habits of the French peasants.As soon as the weather turned cold, people all over France shut themselves away and practiced the forgotten art of doing nothing at all for months on end.

     In line with this, Jeff Warren, a producer at CBC Radio's The Current, tells us that the way we sleep

has changed fundamentally since the invention of artificial (人造的 )lighting and the electric bulb.

     When historians began studying texts of the Middle Ages, they noticed something referred to as “first

sleep”, which was not clarified, though.Now scientists are telling us our ancestors most likely slept in

separate periods.The business of eight hours' uninterrupted sleep is a modern invention.

     In the past, without the artificial light of the city to bathe in, humans went to sleep when it became dark and then woke themselves around midnight.The late night period was known as  “The Watch”. It was

when people actually kept watch against wild animals, although many of them simply moved around or

visited family and neighbours.

     According to some sleep researchers, a short period of insomnia(失眠)at midnight is not a disorder.It

is normal.Humans can experience another state of consciousness around their sleeping, which occurs in the brief period before we fall asleep or wake ourselves in the morning.This period can be an extraordinarily

creative time for some people.The impressive inventor, Thomas Edison, used this state to hit upon many of his new ideas.

     Playing with your sleep rhythms can be adventurous, as anxiety may set in.Medical science doesn't help much in this case.It offers us medicines for a full night's continuous sleep, which sounds natural; however,

according to Warren's theory, it is really the opposite of what we need.

1.The example of the French peasants shows the fact that_____ .

A.people might become lazy as a result of too much sleep

B.there were signs of hibernation in human sleeping habits

C.people tended to sleep more peacefully in cold weather

D.winter was a season for people to sleep for months on end

2.The late night was called “The Watch” because it was a time for people_____.

A.to set traps to catch animals

B.to wake up their family and neighbours

C.to remind others of the time

D.to guard against possible dangers

3.What does the author advise people to do?

A.Sleep in the way animals do.

B.Consult a doctor if they can't sleep.

C.Follow their natural sleep rhythm.

D.Keep to the eighthour sleep pattern.

4.What is the author's purpose in writing the passage?

A.To give a prescription for insomnia.

B.To urge people to sleep less.

C.To analyze the sleep pattern of modern people.

D.To throw new light on human sleep.