A. (A) 150 mm B. (B) 350 mm C. (C) 550 mm D. (D) 750 mm
A. did she realize B. that she realized C. has she realized D. then she realized
A. were B. have C. was D. has
A. to complain B. complaining C. to be complaining D. complain
A. 数据子系统 B. 模型库子系统 C. 用户对话子系统 D. 知识库子系统