问题 单项选择题

设有下列二叉树:


对此二叉树中序遍历的结果为

A) ABCDEF B) DBEAFCC) ABDECF D) DEBFCA

答案

参考答案:B

解析: 二叉树的遍历分为先序,中序、后序三种不同方式。本题要求中序遍历,其遍历顺序应该为:中序遍历左子树→访问根结点→中序遍历右子树。按照定义,中序遍历序列是 DBEAFC,故答案为B。

阅读理解

阅读短文,选择正确选项。

       In the United States, every year, Thanksgiving Day is on the fourth Thursday of November. Because

Canada is north of the United States, and is colder. The harvest comes earlier in the year. In Canada, people have

Thanksgiving Day on the second Monday in October. 

       The harvest brings a lot of food to the people. On Thanksgiving Day people in Canada and America like to

have a big meal with their friends and family just like Chinese people do at Mid-Autumn Festival. Many

Canadians and Americans put flowers, vegetables and fruits around their homes to say "Thank you" for the

harvest.

       At a Thanksgiving Day dinner, many Canadians and Americans will eat turkey, potatoes, and pumpkins pie.

These are food like the food of many years ago. They are saying "Thank you" for the harvest that comes every

year.

1. Which country has the Thanksgiving Day like the United States? [ ]

A. Japan.

B. China.

C. Canada.

D. Korea.

2. In the United States, Thanksgiving is on the fourth Thursday of            . [ ]

A. January

B. May

C. November

D. December

3. Canada has Thanksgiving earlier in the year because             .[ ]

A. they like flowers

B. the harvest come earlier

C. they have a big meal

D. they want to be different

4. The harvest brings               to people.[ ]

A. flowers

B. turkeys

C. food

D. pumpkins

5. What do people usually say on Thanksgiving Day for the harvest? [ ]

A. Good morning.

B. I'm hungry.

C. Hello.

D. Thank you.

多项选择题 案例分析题