请从应用的观点看，计算机软件可以分为哪三类，生来在的主要作用和功能是什么？

Are you looking for some new and exciting places to take your kids (孩子) to? Try some of these places:

Visit art museums. They offer a variety of activities to excite your kids' interest. Many offer workshops for making land-made pieces, traveling exhibits, book signings by children's favorite writer, and even musical performances and other arts.

Head to a natural history museum. This is where kids can discover the past from dinosaur(恐龙) models to rock collections and pictures of stars in the sky. Also, ask what kind of workshops and educational programs are prepared for kids and any special events that are coming up.

Go to a Youtheater. Look for one in your area offering plays for child and family visitors. Pre-show play shops are conducted by area artists and educators where kids can discover the secret about performing arts- Puppet(木偶)making and stage make-up are just a couple of the special offerings you might find.

Try hands-on science. Visit one of the many hands-on science museums around the country. These science play-lands are great fun for kids and grown-ups alike. They'll keep your child mentally and physically active the whole day through while pushing buttons, experimenting, and building. When everyone is tired, enjoy a fun family science show, commonly found in these museums.

小题1:If a child is interested in the universe, he probably will visit

A．a Youtheater

B．an art museum

C．a natural history museum

D．a hands-on science museum小题2:What can kids do at a Youtheater?

A．Look at rock collections.

B．See dinosaur models.

C．Watch puppet making.

D．Give performances.小题3:What does "hands-on science" mean in the last paragraph?

A．Science games designed by kids.

B．Learning science by doing things.

C．A show of kids' science work.

D．Reading science books.小题4:Where does this text probably come from?

A．A science textbook.

B．A tourist map.

C．A museum guide.

D．A news report.

中心城区集聚了市域范围内大量的资源，首位度高，其他城镇的分布呈现围绕中心城区、依赖中心城区的态势，中心城区往往是市域的政治、经济、文化中心。该市域城镇空间组合类型为( )。

A．均衡式

B．单中心集核式

C．分片组团式

D．轴带式

冯·诺依曼结构的计算机的基本原理是______原理。

“广播”有广义和狭义之分，广义的“广播”指______。

A．广播和电视
B．所有电子媒介
C．广播和电视的综合频道
D．面向公众的节目

为保证对故障恢复的支持，登记日志记录时必须先把日志记录写到外存的日志文件中，再把相应的数据库修改写到外存的数据库中。这称作　　【15】　　原则。