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问题 单项选择题

以下叙述不正确的是( )。

A．后序线索二叉树是不完善的，要对它进行遍历，不需使用栈

B．任何一棵二叉树的后序线索树进行后序遍历时都必须使用栈

C．任何一棵二叉树都可以不用栈实现先序线索树的先序遍历

D．任何一棵二叉树都可以不用栈实现中序线索树的中序遍历

答案

参考答案：B

解析：不需要使用栈。

单项选择题 A型题

毒蕈中毒致死最多的一型是（）

A.胃肠炎型

B.神经、精神型

C.中毒性肝炎型

D.溶血型

E.休克型
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单项选择题 案例分析题

Once there was a little girl who came to live in an orphanage (孤儿院). As Christmas time was drawing near, all of the other children 11 telling the little girl about the beautiful Christmas tree that would appear in the hall downstairs on Christmas morning. After their usual 12 , each child would be given their only Christmas gift, a small orange.

The headmaster of the orphanage was very 13 with the kids. So on Christmas Eve, when he 14 the little girl slipping down the stairs to peek（偷看）at the much-heard-of Christmas tree, he 15 that the little girl would not receive her Christmas orange because she had been so curious as to disobey the rules. The little girl ran back to her room 16 , crying at her terrible fate. The next morning as the other children were going down for breakfast, the little girl stayed in her bed. She couldn’t 17 the thought of seeing the others receive their gift while there would be 18 for her. Later, as the children came back upstairs, the little girl was surprised to be handed a napkin (餐巾). As she carefully opened it, there, to her 19 , was an orange all peeled and sectioned (分瓣). “ How could this be? ” she asked. Then, she realized how each child had taken one section from their orange for her so that she, too , would have a Christmas orange. What an example of the true meaning of Christmas those orphan children showed that morning! How I 20 the world would show the same kind of concern for others, not only at Christmas, but throughout the year!

请在19处填上正确答案（）

A.surprise

B.regret

C.sorrow

D.anger
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