Software design is a (66) process. It requires a certain (67) of flair on the part of the designer. Design can net be learned from a book. It must be practiced and learnt by experience and study of existing systems. A well (68) software system is straight forward to implement and maintain, easily (69) and reliable. Badly (68) software systems, although they may work are (70) to be expensive to maintain, difficult to test and unreliable.

70（）

A．like

B．likely

C．unlike

D．unlikely

人才工作“三个留人”是指（）。

A.事业留人

B.环境留人

C.感情留人

D.适当待遇留人