电力系统发生短路时，电网总阻抗会（）。
A、减小；
B、增大；
C、不变；
D、忽大忽小。
参考答案：A
— Why were you not at the concert last night?
— I ______a close game between Seattle Sonics and Miami Bucks. [ ]
A. watched
B. had watched
C. was watching
D. have been watching
校园文化是影响学生发展的因素之一，在课程类型上，它属于( )。
A．科学课程B．活动课程C．隐性课程D．核心课程
