在杆档过渡终结制作时，将光缆内的加强芯与纤芯剥离，开剥长度约为（）。
A.50cm
B.60cm
C.80cm
D.100cm
参考答案：C
The news that Obama was elected president of the United States is not mystery.
A．the；the
B．a；/
C．/；a
D．the；a
简述地热发电系统的类型及其特点？
