若两台主机在同一子网中，则两台主机的IP地址分别与它们的子网掩码相“与”的结果一定（）。

A、为全0

B、为全1

C、相同

D、不同

有三个关系R、S和T如下：则由关系R和S得到关系T的操作是（　　）。

A、并

B、投影

C、交

D、选择

CTAIS服务器端的主要功能是存储业务数据、提供部分业务处理逻辑，确保数据利用的安全、正确、完整、高效。

A、对

B、错

Which three statements correctly describe the features of the I/O calibration process?（）

Only one I/O calibration process can run at a time.

It automates the resource allocation for the Automated Maintenance Tasks.

It improves the performance of the performance-critical sessions while running.

It can be used to estimate the maximum number of I/Os and maximum latency time for the system.

The latency time is computed only when the TIMED_STATISTICS initialization parameter is set to TRUE.

If an external monitor is attached to a laptop and it does not work， which of the following actions should a technician take FIRST？（）

A、Re-install the operating system.

B、Open and close the cover.

C、Use the function key to activate the monitor.

D、Install new software for the keyboard.

When defining a function activity, what is true about the Result Type?（） (Choose two.)

Result Type is optional.

Result Type is mandatory.

Result Type can be changed after it is assigned to the function activity.

Result Type should belong to the same item type as the function activity