问题 单项选择题

用关键字序列10、20、30、40、50构造的二又排序树(二又查找树)为______。

答案

参考答案:C

解析:本题考查数据结构基础知识。 根据关键字序列构造二叉排序树的基本过程是,若需插入的关键字大于树根,则插入到右子树上,若小于树根,则插入到左子树上,若为空树,则作为树根结点。

阅读理解

请品读以下短文,判断句子正(T)误(F)。

     Dogs are friends of man. They work for us. They hunt (狩猎) with us. They play with us. But once,

all over the world, dogs are wild (野生的).

     Dogs go back to the Stoen Age. All dogs had the same ancestor (祖先). It is believed that this

ancestor was much like a wolf (狼). Other animals like the fox, came from this ancestor, too.

     Thousands of years ago, man began to tame (驯服) the wild dogs . When the dogs were tame, they

were trained (训练). The strong dogs became working animals. They were trained to pull heavy loads

(担子). They learned to keep watch over the sheep and other animals. Working dogs had other jobs,

too.

     Some dogs were not strong. But they could help man hunt for game. Other dogs were best as pets.

At first, there were only a few kinds of dogs. Today there are more than 100 kinds.

( )1. The word in the story that means an animal far back in another animal's family is ancestor.

( )2. The story make us believe that Man has helped change animals.                              

( )3. The strong dogs turned into foxes.                                                          

( )4. Dogs are pets from the beginning.                                                          

( )5. Dogs and man have been friends for a long time.                                            

单项选择题