问题 单项选择题

在深度为5的满二叉树中,叶子结点的个数为 ______。

A.32

B.31

C.16

D.15

答案

参考答案:C

解析:
[知识点]二叉树的概念
[评析]所谓满二叉树是指这样的一种二叉树;除最后一层外,每层上的所有结点都有两个子结点。这就是说,在满二叉树中,每一层上的结点数都达到最大值,即在满二叉树的第K层上有2K-1今结点,且深度为m的满二叉树有2m个结点。在满二叉树中,最后一层的结点个数就是叶子结点的个数,本题中深度为5,故叶子结点数为25-1=24=16。

单项选择题
阅读理解

阅读理解。

Dear Editor,

     I'm a Senior 1 student in a middle school. This term, my favourite teacher, Miss Mao, no longer teaches

us. I want to see her, but I'm afraid that she no longer likes me and I don't want to trouble her. I really miss

her. What should I do? 

                                                                                                                                             Tian Yan

Dear Tian Yan,

     It's bad luck that you have lost your favourite teacher. But, if she is still in your school, nothing can stop

you going to see her. When she isn't busy, ask her if she minds having a quick chat. You can then tell her

she was your favourite teacher. Everyone is happy to know they are liked!

     If she has left the school, it will be more difficult to meet her. It will be hard, but remember people always

come and go in our lives. We can't rely on (依靠) them being with us all the time.

     You may be sad to say goodbye to her, but we can remember and learn from her. Think of her best

qualities. 

     You could also try looking for similar qualities in your other teachers. Study hard and give your new

teacher a chance. In time, you might start to see that he or she has different qualities to learn from.

      Finally, you can not completely rely on other people getting you through your studies, or even your life. 

                                                                                                                                                Editor

1. Tian Yan ______. [ ]

A. is a troublemaker

B. likes Miss Mao very much

C. is happy these days

D. doesn't like to tell her secret to anyone

2. Which of the following does the editor advise Tian Yan NOT to do? [ ]

A. Find a time to see Miss Mao.

B. Have a short chat with Miss Mao.

C. Tell Miss Mao she likes her.

D. Keep quiet about the thing.

3. The expression"in time" in this passage means "______". [ ]

A. over a period of time

B. on time

C. at the right time

D. a long time ago

4. According to the passage, students can make progress in their studies ______. [ ]

A. completely by their favourite teachers

B. completely by their favourite classmates

C. mainly by their parents

D. mainly by themselves