室内分布无源器件的接头是（）
A.N型公头
B.K型公头
C.N型母头
D.K型母头
参考答案：C
地球表面划分五代的依据是（ ）
A．各地纬度的高低
B．地面受热状况的差别
C．有无阳光直射和斜射
D．有无极昼、极夜现象
— Did you go to Jim's birthday party?
— No, I . [ ]
A. am not invited
B. wasn't invited
C. haven't been invited
D. didn't invite
