填空题 从供选择的答案中选出应填入英语文句中()内的正确的答案。
Software design is a

• (A) process. It requires a certain
• (B) of flair on the part of the designer. Design can not be learned from a book. It must be practiced and learnt by experience and study of existing systems. A well
• (C) software system is straight forward to implement and maintain, easily
• (D) and reliable .Badly(C) software systems, although they may work are
• (E) to be expensive to maintain, difficult to test and unreliable.
  A: ① create ② created ③ creating ④ creative
  B: ① amount ② amounted ③ mount ④ mounted
  C: ① design ② designed ③ designing ④ designs
  D: ① understand ② understands ③ understanding ④ understood
  E: ① like ② likely ③ unlike ④ unlikely