结构推理从下列英语叙述中，选出5条正确的叙述。
1．When the electricity is switched off, the ROM is cleared ofits contents, the RAM is not.
2．IF-THEN-ELSE structures in a programming language provide selection.
3．A program in its original form is known as an object program, and the translated version is known as a source program.
4．The CPU is the most important piece of hardware in the entire system and yet one of the simplest.
5．The lowercase letters come after the uppercase letters in the ASCII table.
6．Queue insertions and deletions are made at the same end ofthe queue.
7．Improvements in software quality are necessary to reduce program maintenance costs.
8．A recursive procedure is one that activates itself during its activations.
9．A floppy diskette machine is an example of a direct access storage device.
10．Comments specify actions for a computer to perform when a program is run.

【正确答案】2 5 7 8 9

【答案解析】这种题型主要考查专业知识，基本概念要清楚。
(1)中，switch off的意思是“关闭”；clear of的意思是“清除”。
(2)中，be known as的意思是“被称为、叫做”。
(8)中，that activates itself during its activations是一个定语从句，修饰和限定one，one指a procedure。
[参考译文]1．当电源关闭时，ROM中的内容被清除，而RAM中的内容不被清除。
2．编程语言中IF-THEN-ELSE的结构提供了选择。
3．一个原始形式的程序也叫做目标程序，而它的解释版本也叫做源程序。
4．CPU是整个系统的硬件中最重要的部分，然而也是最简单的。
5．在ASCII表中，小写字母在大写字母的后面。
6．队列的插入和删除都在队列的同一端。
7．软件质量的提高必然降低程序维修成本。
8．一个递归过程是在自己活动期间激活自身。
9．软盘机是直接访问存储设备的一个范例。
10．当计算机运行时，注释指定计算机要执行的行为。