PMS系统运行的基础数据中设备台账录入工作生成了电气设备对象数据单线图生成了电气设备之间的拓扑关系，这两种数据完整构成电网设备模型，缺一不可。
参考答案：错
Only when students _____ willing to learn can they be active _____ learning activities. [ ]
A. will become; in
C. become; with
C. will become; for
D. become; in
直通式升降止回阀只能安装在垂直管路上。
