软件的(51)是指软件从一种计算机系统转换到另一种计算机系统运行的难易程度。在规定的条件下和规定的时间间隔内，软件实现其规定功能的概率称为(52)。

Firewall is a(74) mechanism used by organizations to protect their LANs from the Internet.

In(75) programming, the user determines the sepuence of instions to be executed, not programmer.

C++ fully supports(73)programming.

(72) is the conscious effort to make all jobs similar, routine, and interchangeable.

(71 ) is the sending and receiving of the messages by computer. It is a fast, low-cost way of communicating worldwide.

In C language,(69) are used to create variables and are grouped at the top of a program block.

An(70) statement can perform. a calculation and store the result in a variable so that it can be used later.

(68) are those programs that help find the information you are trying to locate on the WWW．

(66) is a device that converts images to digital format．

In C language, a(67) is a series of characters enclosed in double quotes．