Software engineering is the science and art of specifying, designing, implementing, and (66) with economy, timeliness and elegance, programs, (67) and operating procedures whereby computers can be made useful to humanity.

This definition implicitly sets (68) the basic goal of software engineering research and development: The basic goal of software engineering is to facilitate specification, design, implementation and evolution of programs, documentation and operating (69) which are useful to humanity in an economic, (70) and elegant manner (using the appropriate science and art).

（70）处填（）。

A．space

B．timely

C．spatial

D．environment

1887年3月，（）将以前脱离矿务局而另设的中国铁路公司改名为中国天津铁路公司

A.段祺瑞

B.李鸿章

C.袁世凯

D.冯国璋