区分不同产业的标志是（）。 A.经济特征 B.市场结构 C.竞争战略 D.产业内战略

Passage Four

The other day an acquaintance of mine, a gregarious and charming man, told me he had found himself unexpectedly alone in New York for an hour or two between appointments. He went to the Whitney and spent the "empty" time looking at things in solitary bliss. For him it proved to be a shock nearly as great as falling in love to discover that he could enjoy himself so much alone.

What had he been afraid of, I asked myself That, suddenly alone, he would discover that he bored himself, or that there was, quite simply, no self there to meet But having taken the plunge, he is now on the brink of adventure ; he is about to be launched into his own inner space, space as immense, unexplored, and sometimes frightening as outer space to the astronaut. His every perception will come to him with a new freshness and, for a time, seem startlingly original. For anyone who can see things for himself with a naked eye becomes, for a moment or two, something of a genius. With another human being present vision becomes double vision, inevitably. We are busy wondering, what does my companion see or think of this, and what do I think of it The original impact gets lost, or diffused.

"Music I heard with you was more than music. " Exactly and therefore music itself can only be heard alone Solitude is the salt of personhood. It brings out the authentic flavor of every experience.

"Alone one is never lonely: the spirit adventures, walking in a quiet garden, in a cool house, abiding single there. "

Loneliness is most acutely felt with other people, for with others, even with a lover sometimes, we suffer from our differences of taste, temperament, mood Human intercourse often demands that we soften the edge of perception, or withdraw at the very instant of personal truth for fear of hurting, or of being inappropriately present, which is to say naked, in a social situation. Alone we can afford to be wholly whatever we are, and to feel whatever we feel absolutely. That is a great luxury!

For me the most interesting thing about a solitary life, and mine has been that for the last twenty years, is that it becomes increasingly rewarding. When I can wake up and watch the sun rise over the ocean, as I do most days, and know that I have an entire day ahead, uninterrupted, in which to write a few pages, take a walk with my dog, lie down in the afternoon for a long think (why does one think better in a horizontal position), read and listen to music, I am flooded with happiness.

I am lonely only when I am overtired, when I have worked too long without a break, when for the time being I feel empty and need filling up. And I am lonely sometimes when I come back home after a lecture trip, when I have seen a lot of people and talked alot, and am full to the brim with experience that needs to be sorted out.

Then for a little while the house feels huge and empty, and I wonder where my selfish hiding. It has to be recaptured slowly by watering the plants, perhaps, and looking again at each one as though it were a person, by feeding the two cats, by cooking a meal.

It takes a while, as I watch the surf blowing up in fountains at the end of the field, hut the moment comes when the world falls away, and the self emerges again from the deep unconscious, bringing back all I have recently experienced to be explored and slowly understood, when I can converse again with my hidden powers, and so grow, and so be renewed, till death do us part.

What do you think is the main idea of the passage Analyze the overall structure of the passage to support yourself.

阅读理解

       Do you want to improve your memory?Are you struggling to remember names and faces as you get

older?Try picking up the phone and speaking to someone.Scientists have found that holding a simple

conversation could be just as effective as playing popular 'braintraining' games that have reproduced a

multimillion pound industry.

      Researchers compared 36 studies on memory exercises performed between 1970 and 2007.Some

studies suggested both healthy older adults and those with mild cognitive impairment (轻度认知缺陷)

could remember words better after some memory training.

However,other studies found this improvement was matched by those who were asked to hold a

discussion about art.

     The finding that social interaction could be just as effective at keeping memory loss at bay comes after Age Concern warned more than a million people aged over 65 lived alone in their own homes.The charity warned solitary lifestyles were a 'silent epidemic (静默的流行病)'spreading through the nation quickly.

      Dr Martin said most people experienced a cognitive decline in old age.This can include memory loss

and inability to plan,pay close attention or perform tasks as quickly as before.The normal rate of decline

seems to speed up in some people,leading to a condition called mild cognitive impairment,which some

researchers see as a reason for developing mental diseases later in life.

      Although several studies have suggested that braintraining exercises could delay signs of cognitive

decline,the studies and the types of training have many different kinds.The findings do not mean that longer,more intense or different exercises might not be effective,but that those which have been reported thus far

have only limited effect.

      Dr Martin concluded researchers needed to improve the way they used their studies to eventually

determine ways of preventing cognitive decline in old age.

1．What is the main idea of Paragraph 1?

A．People should play more 'braintraining' games.

B．Training has a great effect on our health.

C．Having a conversation can improve memory

D．People have no ways to improve memory

2．What does the underlined word "solitary" probably mean?

A．Unhealthy.  

B．Alone.

C．Enjoying being alone. 

D．Lacking patience.

3．Mild cognitive impairment can cause people to ________.

A．have mental diseases

B．develop physical diseases

C．worry about the coming of old age

D．escape from the reality in life

4．What message can be implied in the passage?

A．Most people suffer from memory loss.

B．There are more social problems to be settled at present.

C．No one can prevent old age from coming.

D．Whether "braintraining" exercises have a great effect on memory is not sure.

5．The passage would be of great help to ________.

A．children 

B．housewives

C．elderly people 

D．badtempered people

（1）用化学符号表示：①2个铝原子     ；②3个硫酸根离子    ；③氯化铁   。

（2）某元素原子结构示意图如图所示，该元素核电荷数为   ，属于    元素（填“金属”或“非金属”）。

桩身内力测试时，传感器的设置位置及数量应符合哪些规定？