目前常用的标准图形系统有（）。
A、CORE
B、GKS
C、PHIGS
D、UNIX
E、AutoCAD
参考答案：A, B, C
We would have called a taxi yesterday if Harold ________ us a ride home.[ ]
A. didn't offer
B. wouldn't offer
C. hasn't offered
D. hadn't offered
医疗机构药剂科（institutional pharmacy）
