问题 单项选择题

某公司的部门(部门号,部门名,负责人,电话)、商品(商品号,商品名称,单价,库存量)和职工(职工号, 姓名, 住址)三个实体之间的关系如表1、表2 和表3 所示。假设每个部门有一位负责人和一部电话,但有若干名员工;每种商品只能由一个部门负责销售。 a. 若部门名是唯一的,请将下述部门SQL 语句的空缺部分补充完整。 CREATE TABLE 部门(部门号CHAR(3) PRIMARY KEY, 部门名 CHAR(10) () , 负责人 CHAR(4), 电话 CHAR(20)) () ) ;

部门名 CHAR(10)()

A.NOT NULL

B.UNIQUE

C.KEY UNIQUE

D.PRIMARY KEY

答案

参考答案:B

完形填空

Some time ago, two navy officers made a journey to the deepest point on the earth. The two men went down seven miles to the__1__of the Pacific Ocean inside a small steel ball to find out if there are any__2__of life.

They set out early so that the ball would come to the surface in the__3__and so be easily found by the mother ship. The divers began__4__at dawn and soon afterwards the ball__5__under the surface of the water.

__6__, the temperature dropped to freezing point and the men trembled inside the ball. They kept in touch with the mother ship by telephone__7__how they felt. At a depth of 3,000 feet, the telephone stopped working and they were quite cut__8__from the outside world. At 30,000 feet, the men were shocked by a sudden loud__9__- even the smallest hole in the ball would have__10__instant death. Luckily, it was only one of the outer windows__11__had broken.

Soon afterwards, the ball__12__the soft ocean floor, raising a big cloud of "dust" made__13__different kinds of small, dead sea animals. Here, powerful lights lit up the __14__water. The men were surprised to see fish swimming just above them, quite__15__ by the very large water pressure. But they did not__16__to leave lights on for long, as the great__17__from them made the water boil. Quite__18__, the telephone began working again and the weak__19__ clear voices of the officers were heard on the mother ship. After a__20__of thirty minutes the men began their journey up, arriving three hours later.

1. A. foot          B. base         C. bottom       D. tip

2. A. marks         B. signs        C. signals       D. messages

3. A. evening        B. night       C. secret        D. daytime

4. A. diving         B. rising       C. traveling      D. preparations

5. A. disappeared    B. floated       C. threw        D. flew

6. A. In time        B. On time      C. At times      D. At one time

7. A. guiding       B. realizing      C. describing     D. imagining

8. A. down         B. over         C. off           D. out

9. A. voice         B. noise        C. explosion     D. shout

10. resulted         B. suggested     C. meant        D. saved

11. A. where        B. that          C. which        D. whose

12. A. touched      B. visited        C. attacked      D. landed

13. A. of           B. from        C. up of         D. into

14. A. green        B. blue          C. dark         D. hot

15. A. unbelieved    B. unchanged    C. uncovered     D. untroubled

16. A. use          B. need         C. dare          D. think

17. A. light         B. heat         C. pressure       D. sound

18. A. unexpected    B. uncovered    C. unknown      D. uncontrolled

19. A. or           B. and          C. but           D. either

20. A. living        B. stay          C. rest          D. break

单项选择题