某330kV输电线路的等值电路如题50图所示,已知=150-j20MVA,线路始端功率及始端电压为()。
A.
B.
C.
D.
参考答案:C
She knows so much about England. She _____ there before.[ ]
A. must be
B. must live
C. must have been
D. must have lived in
肛瘘的治疗原则有哪些?