计算：3-1+8×|-13|=______．

肺部肿块出现“爆玉米花”样的钙化特征多见于（）

A.肺炎

B.肺脓肿

C.肺结核

D.肺癌

E.肺错构瘤

如图所示，把中心带有小孔的平行放置的两个圆形金属板M和N，连接在电压恒为U的直流电源上．一个质量为m，电荷量为q的微观正粒子，以近似于静止的状态，从M板中心的小孔进入电场，然后又从N板中心的小孔穿出，再垂直进入磁感应强度为B的足够宽广的匀强磁场中运动（忽略重力的影响）．那么：

(1)该粒子从N板中心的小孔穿出时的速度有多大？

(2)若圆形板N的半径为R，如果该粒子返回后能够直接打在圆形板N的右侧表面上，那么该磁场的磁感应强度B至少为多大？

重力是由于地球的吸引而使物体受到的力，重力的施力物体是       ．

阅读理解。

      One-hundred-and seventh birthdays aren't usually celebrated for authors who aren't alive anymore.

But Theodor Seuss Geisel-better known as the children's books author Dr. Seuss -who came into the

world on 2 March, 1904, was an unusual man.

     Like generations of children I was raised on his wonderful stories. But when I now read them to my

children it's not just the childhood memories I enjoy. His writing is brilliant and imaginative and flows with

a self-confidence as sure as the words of a Shakespeare poem. Readers ride his characteristic rhythm (韵律) with an effortless joy that cannot be matched by any other modern writer:

     You have brains in your head

     You have feet in your shoes

     You can steer yourself any direction you choose

     And will you succeed?

     Yes indeed, yes indeed!

     Ninety-eight and three-quarters percent guaranteed.

     Seuss's brilliant cartoons and clever words make his books a delight for adults but they attract mostly

children of course. His stories teach kids moral lessons but in indirect and entertaining ways.

     The first Seuss book I was given was The Lorax, written just as the 60s were becoming the 70s.

Seuss was ahead of his time, and in this book the dawn of concern for environmental problems are shown as the Lorax "who speaks for the trees" battles against an evil businessman who wants to destroy the

forest and make goods "which everyone needs".

     It's not only a warning of the heavy price of environmental destruction, written well before most people had thought to worry, but it's also a smart analysis of consumer societies: "Unless someone like you cares

a whole awful lot, nothing is going to get better. It's not." This is of course a moral message, but not of the kind designed to persuade the youngsters into behavior that adults want.

I could go on, but hey, it's a birthday, and I'm sure you folks have some good toasts to raise for the party…

1. What's the purpose of this passage?

A. To introduce Dr. Seuss's life.          

B. To analyze Dr. Seuss's books.

C. To describe Dr. Seuss's writing style.

D. To celebrate Dr. Seuss's achievements.

2. Why does the author include Dr. Seuss's poem? 

A. To encourage readers to use their brains and choose their own way.

B. To give readers a sample of Seuss's story The Lorax.

C. To provide readers with an example of Seuss's writing style.

D. To explain how relevant Seuss's stories remain today.

3. Why do adults also enjoy Seuss's books? 

A. His words and pictures are imaginative enough to be enjoyed by all.

B. His books give children obvious moral messages to learn from.

C. He writes about adult topics in a way that is understandable to children.

D. He was the first person to write about the environment.

4. When was the book The Lorax written?

A. Early 1960s.    

B. Early 1970s.  

C. Late 1960s.  

D. Late 1970s.

5. Which of the following is true about Seuss?  

A. Many of the issues he discussed attracted greater concern in later years.

B. He is widely considered as the twentieth-century Shakespeare.

C. His books are more popular now than when they were first published.

D. Most readers thought his ideas were difficult to understand.

汽轮机轴瓦两侧及前后间隙不一致时，应首先查清哪些原因？