电线积冰观测中的直径必须大于厚度。（）
参考答案：错
Mary _____ her job as an agent in a travel agency in September and moved to Canada in search
of new opportunities there.[ ]
A. exposed
B. resigned
C. appointed
D. required
按监控对象按电特性分（）。
A.非电量和电量
B.模拟量和数字量
C.智能和非智能
