不适用于 * * 冲洗()A． * * 手术前准备 B．上镭后 C．滴虫性 * * 炎 D．产后3天内

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

How does the developer of a large database system achieve (1) and data independence How does the developer make certain that stored items are (2) and do not simply disappear in the immensities of the database, as if in quicksand

One solution is to set up a (3) system, in which all data (the internal level), all records and files (the conceptual level), and all user interfaces (the external level) are controlled by one central programming group. This may seem the most useful solution. But worldwide enterprises such as the meteorological and satellite tracking networks, IBM, and General Motors gather and record information at a very large number of locations. To stay flexible and avoid top - heaviness, such an organization might want to avoid excessive centralization.

A centralized system is (4) , but it may not be responsive to user needs. This is particularly true in a large organization - the worldwide meteorological network, for example, Data-gathering methods in the Himalayas, the equatorial jungles are different in very possible way. It is reasonable to believe that the best choices for the corresponding data storage and access structures ought to be just as different. A centralized database system would not (5) such differences.

4（）

A．good

B．inefficient

C．efficient

D．useful

分离空肠弯曲菌常用的培养基为

A．改良Skirrow培养基
B．TCBS培养基
C．SS培养基
D．MaC培养基
E．GN培养基

土壤潜育化

8086CPU，若NMI、除法中断和INTR同时产生，则CPU执行完当前指令后对中断请求的检测顺序为（）。

A.NMI、除法中断、INTR

B.NMI、INTR、除法中断

C.INTR、除法中断、NMI

D.除法中断、NMI、INTR

预聚合反应器的停留时间一般在（）分钟。

A、4

B、4~10

C、15

D、20