程序中已构成如下图所示的不带头结点的单向链表结构，指针变量s_爱下问搜题

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问题单项选择题

程序中已构成如下图所示的不带头结点的单向链表结构，指针变量s、p、q均已正确定义，并用于指向链表结点，指针变量s总是作为头指针指向链表的第一个结点。

若有以下程序段：
q=s; s=s-＞next; p=s;
while (p-＞next) p=p-＞next;
p-＞next=q; q-＞next=NULL;
该程序段实现的功能是( )。

答案

参考答案：A

解析：因为刚开始时s指向a结点(链表头)，所以语句q=s；使q也指向a结点。s=s-＞next；语句使s指向a的下一个结点b。p=s;语句使p也指向b结点。接下来是一个while循环，循环条件为 p-＞next，即当p没有指向链表尾时执行循环体p=p-＞next；让p指向下一个结点，所以当循环结束时，p指向链表尾(c结点)。执行到此时，s、p、q分别指向的结点是b、c、a。然后执行p-＞next=q;，使c结点的后续指针指向了a结点。最后执行q-＞next=NULL;，使a结点的后续指针为NULL。由此可见，该程序段实现了将a结点移动到c结点之后，即首结点成为尾结点。故应该选择A。

听力题

单词拼写（15分）

1. Since 1965, the m_________ leaf has been the centerpiece of the National Flag of Canada.

2. When the white liquid was m ________ with water, it became blue at once.

3. Wal-Mart has many chain stores all over the world and you may find one w______ a short

walk along a busy street in any big city.

4. There are seven c ______ in the world, of which Asia is the largest.

5. There are many tall trees in our city, some m ________ over 20 meters.

6. At daybreak, our ship entered Shanghai __________ ( 海港 ).

7. I like sitting on the top of the hill watching the fields in the ____________ (在远处 ).

8. Some people are t____________( 恐惧的) of heights, so they dare not climb high.

9. The news that there are some people who have died of A/ H1N1 has been ______(确认).

10. Our school lies in the suburbs, and many students like to go _________( 往市区) to buy what they need.

完形填空

As a kid, I spent my summers with my grandparents in Texas. And every few summers, we’d __16__ the caravan (旅游团队), a group of Airstream trailer owners who __17__ together around the U.S. and Canada．
I loved and worshipped my grandparents and I really looked __18__ to these travels. On one particular __ 19__ ，I was about 10 years old. I was rolling around in the backseat. My grandfather was __20__ . And my grandmother had the passenger seat. She smoked throughout these trips, and I hated the __21__.
At that age, I’d take any excuse to make estimates(估计) and do minor __22__．At any rate, I decided to do the math for my __23__. I estimated the number of cigarettes per days, estimated the number of __24__ per cigarette and so on. When I was satisfied that I’d come up with a reasonable number, I poked my head into the __25__ of the car, tapped my grandmother __26__ the shoulder, and proudly proclaimed, “At two minutes per puff, you've taken nine years off your __27__!” Because the ad said, every puff of a cigarette takes some number of minutes __28__ smoker’s life．
I expected to be applauded for my __29__ and arithmetic skills. That’s not what happened．__30__, my grandmother burst into __31__. I sat in the backseat and did not know what to do. My grandfather was a highly intelligent, __32__ man. He had never said a harsh word to me. He pulled __33__ onto the shoulder of the highway. He stopped and got out of the car, __34__ me, and after a bit of silence，he gently and __35__ said, “Jeff, one day you’ll understand that it’s harder to be kind than clever.”

A．arithmetic(算数)

A．grandfather

B．grandmother

D．puffs(烟头)

C．Unfortunately