Computers will become more advanced and they will also become easier to use.Improved speed recognition will make the operation of a computer easier.Virtual reality(虚拟现实),the technology of (71) with a computer using all of the human senses,will also contribute to better human and computer (72). Other, exotic(奇异的) models of computation are being developed,including biological conputing that uses living organisms,molecular computing that uses molecules with particular (73),and computing that uses DNA,the basic unit of heredity(遗传),to store data and carry out operations.These are examples of possible future computational platforms that,so far,are limited in abilities or are strictly (74). Scientists investigate them because of the physical limitations of miniaturizing circuits embedded in silicon. There are also (75) related to heat generated by even the tiniest of transistors.

（74）处填（）。

A．empirical

B．real

C．practical

D．theoretical

下列叙述中，正确的是______。

A) 编译程序、解释程序和汇编程序不是系统软件
B) 故障诊断程序、排错程序、人事管理系统属于应用软件
C) 操作系统、财务管理程序、系统服务程序都不是应用软件
D) 操作系统和各种程序设计语言的处理程序都是系统软件