问题 单项选择题

对于二叉查找树(Binary Search Tree),若其左子树非空,则左子树上所有节点的值均小于根节点的值:若其右子树非空,则右子树上所有节点的值均大于根节点的值;左、右子树本身就是两棵二叉查找树。因此,对任意一棵二叉查找树进行 (58) 遍历可以得到一个节点元素的递增序列。在具有n个节点的二叉查找树上进行查找运算,最坏情况下的算法复杂度为 (59)

(58)处填()。

A.先序

B.中序

C.后序

D.层序

答案

参考答案:B

解析:

参考2008年12月真题60的分析中的排序二叉树的性质可知58题应该是中序。

阅读理解

阅读理解。

     Spending just a few hours a week online may make people feel more socially isolated(孤立的),

lonely and downhearted(沮丧的), according to a two-year study of nearly 100 families with the

Internet.

     "We were surprised to find that social technology has such bad effects on social communications,"

the lead author, Dr. Robert Kraut of Carnegie Mellon University in Pittsburgh, Pennsylvania, said in a

statement to the news. The findings suggest that "Rather than encourage students to use the Internet

alone for research, teachers might give pupils online group homework to complete with classmates.

Local groups might build websites that allow neighbors to discuss local affairs(地方事务)."

     "Before the technology develops and can be really more beneficial, people should control(控制)

their wishes to use much of the Internet," Dr. Kraut and other experts advise. In order to control their

children and encourage family activities, parents might think of putting the computer in the living room

rather than in a child's room, they suggest.

     Dr. Kraut also suggests that when surfing on the net, especially when chatting with strangers on the

net, children should not use their real names, and that they should not tell the addresses, telephone

numbers to the strangers.

1. According to the research, surfing on the Internet can make people feel more            .

A. excited              

B. communicative

C. lonely                

D. happy

2. This study was made by            .

A. 100 families

B. Dr. Kraut and other experts

C. the newspaper

D. Dr. Kraut only

3. This research work took          .

A. a week          

B. a few hours

C. two years        

D. more than 100 days

4. According to the context(上下文), "beneficial" means "            " in Chinese.

A. 有害的        

B. 发展的

C. 有趣的        

D. 有益的

5. Which of the following do the experts suggest?

A. Teachers should ask the students to finish their homework alone on the Internet.

B. Schools should build websites for students to discuss problems on the Internet.

C. Instead of putting the computer in the sitting room, parents should put it in a child's room.

D. Children should not give their real names, addresses or telephone numbers to the strangers.

单项选择题