问题 填空题

设一棵完全二叉树共有500个结点,则在该二又树中有______个叶子结点。

答案

参考答案:250

解析: 根据二叉树的性质:具有n个结点的完全二叉树,其父结点数为int(n/2),而叶子结点数等于总结点数减去父结点数。

选择题
完形填空

Peter Fern was crazy about mountains. Climbing was the  1 of his life. Church towers,seaside cliffs, rock faces, ice mountains,anything “If it is there” , he used to say, “then I want to climb it.”

So the news of his marriage gave me a   2 . I’d never known him to take much interest in   3 . Well,Peter Fern a married man! I couldn't  4 it. I  5 whether his wife would try to stop some of his risky   6 .

She was French perhaps--from that place   7 he usually spent his holidays. Chamonix,wasn’t it? From Chamonix he'd climbed Mount Blanc on his seventeenth birthday, and another one the day after! That was it, then: She was French,from a mountaineering family. No  8 . No other explanation.

A month later I met them  9 in town. Anna surprised me—because she was English. She was a dancer in the   10

“I have   11 climbed more than sixty steps in my life,” she told me. “Peter has his   12 , and I’ve got mine. No   13 ”. “None at all,”Peter said, smiling. “Where did you spend your   14 ?” I askeD.Somewhere far  15 theatres and mountains,was it? “We had a week's holiday,” Anna said, “I flew to New York to see Dirke Dancers on Broadway. A wonderful  16 !” Peter said, “I didn’t want to   17 the good weather. So I went to Switzerland and climbed the north   18 of the Eiger with Allen Dunlop. Great   19 , the Eiger. Grand place for a honeymoon! I’ll show you the   20 we took one day.”

1. A.purpose                B.love                  C.answer                  D.even

2. A.joy                       B.thought              C.lesson                   D.shock

3. A.mountains             B.churches            C.faces                    D.girls

4. A.accept                  B.understand         C.bear                     D.tell

5. A.believed               B.knew                 C.wondered              D.realized

6. A.jobs                     B.words                C.adventures            D.deeds

7. A.where                   B.when                 C.which                   D.how

8. A.one                      B.reason               C.sign                      D.doubt

9. A.all                    B.two                   C.both                     D.double

10.A.family              B.mountain           C.theatre                  D.holiday

11.A.ever                    B.even                  C.never                    D.almost

12.A.interests               B.life                    C.room                    D.car

13.A.wonder            B.way                   C.time                     D.problems

14.A.days                    B.honeymoon        C.childhood             D.rest of life

15.A.away                   B.as                      C.by                        D.from

16.A.show                   B.sight                  C.scene                    D.game

17.A.miss                    B.escape               C.break                    D.forget

18.A.position               B.face                   C.point                    D.line

19.A.programme          B.progress             C.fun                       D.invention

20.A.photographs         B.roles                  C.sports                   D.pains