问题
单项选择题
有三个关系R,S和T如下：
其中关系T由关系R和S通过某种操作得到，该操作为（）
A．选择
B．投影
C．交
D．并
答案
参考答案：D
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有三个关系R,S和T如下：
其中关系T由关系R和S通过某种操作得到，该操作为（）
A．选择
B．投影
C．交
D．并
参考答案：D
Questions 29-40
· Read the information about the communication of information in business.
· Choose the correct word to fill each gap from A, B or C.
· For each question (29-40) mark one letter A, B or C on your Answer Sheet.
| A number of business people still believe that information is power and constantly question how (29) people need to know. As a result, they tell employees (30) as much as they think is essential (31) them to do particular jobs. Furthermore, (32) business people have been taught (33) to communicate effectively and (34) they communicate very badly at all levels. Recent research shows that (35) most serious problems experienced by modern business are communication (36) Research has also shown that there is a clear link (37) good communication in a business and the motivation of the employees. Newsletters and notices are not (38) It is the attitude and behavior of business managers which (39) all the difference. Unfortunately, at present, a lot of employees do not believe all the information they receive from their managers (40) they feel that the managers themselves are out of touch with their staff. |
A．
| A. making |
B．
| B. made |
C．
| C. make |