问题 实验题

给你一个电池组,一只电流表,一只已知阻值的定值电阻R,以及开关、导线.用这些器材测一个未知阻值的电阻Rx的阻值.

要求:

(1)画出电路图;

(2)写出主要步骤和计算式.

答案

(1)

(2)实验步骤:

闭合S1,断开S2,测量定值电阻R的电流I1

闭合S2,断开S1,测量被测电阻RX的电流I2

RX=

阅读理解

     She is a cute,  quiet girl. As a daughter,  she has no secrets from her mother,  who is very pleased with her. But recently she has become somewhat mysterious,  and not so open as before. She has a diary that

she keeps under lock and key. Her mother cannot help worrying about her: what if she falls in love, which

is too early for a girl of her age.After all she is reaching the "dangerous stage".These thoughts have caused

trouble in the mother's mind.

     One weekend the girl came to tell her mother that she was going to the cinema with her schoolmate

and would return late. This was the first time her mother agreed,  and she couldn't help worrying because

her daughter had never been away at night before. The mother waited till nine and her uneasiness got the

upper hand over her. She decided to go out to meet her daughter. Just at that moment the noise of a car

pulling up drew her to the window and-there was her daughter,  waving goodbye to a boy. Her heart

missed a beat. When the girl came in,  the mother was watching TV,  pretending nothing had happened. "Mum I'm back." "Yeah." "Sorry to be late. Still sitting up?" "Yes,  Oh,  that…Who's that boy?" The

daughter was stunned for a moment. "Ah. It's my monitor. He gave me a lift on his way home. Mum,  

I'm going to bed." "All right. Go to sleep early."

    Next morning when the mother went to the daughter's room to do some tidying,  she found her diary left at her pillow. After a few minutes' hesitation she eventually opened it to the entry of the night before. It read: Mum,  it's love that made you ask,  but it would show your understanding of me if you hadn't.

Holding the diary,  the mother fell into thought.

1.Which is the correct order according to the story?

a. She took a lift back in her monitor's car.

b. She went to see a film with her classmate.

c. She wrote in her diary to her mother.

d. Her mother pretended to watch TV.

e. Her mother worried about her daughter's returning late.

A.b,  e,  a,  d,  c  

B.e,  b,  a,  d,  c

C.b,  a,  e,  d,  c  

D.b,  e,  a,  c,  d

2.Which of the following is TRUE according to the story?

A.The girl knew her mother would ask her the question about the boy.

B.What the daughter did recently had worried her mother.

C.The mother was eager to read her daughter's diary the next day.

D.The girl's diary was always unlocked.

3.The main purpose of this article is to show that parents should________.

A.care about what their children really think and feel

B.not give much freedom to their children

C.talk with their children about their early love

D.keep silent about their children's privacy(隐私)

4.Which can be the best title for this story?

A.Mother's True Love

B.Early Love Between Students

C.To Ask or Not To Ask

D.Dangerous Age

问答题

[说明] 邻接表是图的一种顺序存储与链式存储结合的存储方法。其思想是:对于图G中的每个顶点 vi,将所有邻接于vi的顶点vj连成一个单链表,这个单链表就称为顶点vi的邻接表,其中表头称作顶点表结点VertexNode,其余结点称作边表结点EdgeNode。将所有的顶点表结点放到数组中,就构成了图的邻接表AdjList。邻接表表示的形式描述如下: #define MaxVerNum 100 /*最大顶点数为100*/typedef struct node{ /*边表结点*/ int adjvex; /*邻接点域*/ struct node *next;/*指向下一个边表结点的指针域*/ }EdgeNode;typedef struct vnode{ /*顶点表结点*/ int vertex;/*顶点域*/ EdgeNode *firstedge; /*边表头指针*/}VertexNode;typedef VertexNode AdjList[MaxVerNum]; /*AdjList是邻接表类型*/typedef struct{ AdjList adjlist; /*邻接表*/ int n; /*顶点数*/}ALGraph; /*ALGraph是以邻接表方式存储的图类型*/ 深度优先搜索遍历类似于树的先根遍历,是树的先根遍历的推广。 下面的函数利用递归算法,对以邻接表形式存储的图进行深度优先搜索:设初始状态是图中所有顶点未曾被访问,算法从某顶点v出发,访问此顶点,然后依次从v的邻接点出发进行搜索,直至所有与v相连的顶点都被访问;若图中尚有顶点未被访问,则选取这样的一个点作起始点,重复上述过程,直至对图的搜索完成。程序中的整型数组visited[]的作用是标记顶点i是否已被访问。[函数]void DFSTraverseAL(ALGraph *G)/*深度优先搜索以邻接表存储的图G*/{ int i; for(i=0;i< (1) ;i++) visited[i]=0; for(i=0;i< (1) ;i++)if( (2) ) DFSAL(G,i);}void DFSAL(ALGraph *G,int i) /*从Vi出发对邻接表存储的图G进行搜索*/{ EdgeNode *p; (3) ; p= (4) ; while(p!=NULL) /*依次搜索Vi的邻接点Vj*/ { if(! visited[ (5) ]) DFSAL(G, (5) ); p=p->next; /*找Vi的下一个邻接点*/ }}