染色其他混纺奶酪布,薄细布,巴里

正常骨髓中呈短T₁和中等T₂信号的成分主要为（）

A.红骨髓

B.黄骨髓

C.矿物质

D.纤维组织

E.血管

阅读理解。

     How many people have I met who have told me about the book they have been planning to write

but have never yet found the time? Far too many.

    This is Life, all right, but we do treat it like a rehearsal (排演) and, unhappily, we do miss so many

of its best moments.

    We take jobs to stay alive and provide homes for our families always making ourselves believe that

this style of life is merely a temporary state of affairs along the road to what we really want to do. Then,

at 60 or 65, we are suddenly presented with a clock and several grandchildren and we look back and

realize that all those years waiting for Real Life to come along were in fact real life.

    In America they have a saying much laughed at by the English:"Have a nice day". They speak slowly

and seriously in their shops, hotels and sandwich bars. I think it is a wonderful phrase, reminding us, in

fact, to enjoy the moment: to value this very day.

    How often do we say to ourselves, "I'll take up horse-riding (or golf, or sailing) as soon as I get a

higher position," only to do none of those things when I do get the higher position.

    When I first became a reporter I knew a man who gave up a very well paid respectable job at the

Daily Telegraph to go and edit a small weekly newspaper. At the time I was astonished by what

appeared to me to be his completely abnormal (反常的) mental state. How could anyone turn his back

on Fleet Street in central London for a small local area? I wanted to know.

    Now I am a little older and possibly wiser, I see the sense in it. In Fleet Street the man was under

continual pressure. He lived in an unattractive London suburb and he spent much of his life sitting on

Southern Region trains.

1. The first paragraph of the passage tells us that         . 

A. we always try to find some time to write a book

B. we always make plans but seldom accomplish them

C. we always enjoy many of life's best moments

D. we always do what we really want to do

2. The underlined phrase "turn his back on" (paragraph 6) most probably means        . 

A. leave for      

B. return to    

C. give up      

D. rely on

3. The man ( paragraph 6) left his first job partly because he was          . 

A. in an abnormal mental state      

B. under too much pressure

C. not well paid                  

D. not respected

4. What is probably the best title for the passage? 

A. Provide Homes For Our Family  

B. Take Up Horse-riding

C. Value This Very Day            

D. Stay Alive

石灰的陈伏期应为( )。

A．两个月以上
B．两星期以上
C．一个星期以上
D．两天以上

环境污染主要来自于对能源的利用，目前主要的能源是（）。

A.化石能源

B.煤炭能源

C.电磁能能源

D.核裂变能

简述原核基因组的特点。