雷电的二次危害是指（）。
A、直接雷击危害
B、雷电流静电感应
C、感应雷击危害
D、雷电波侵害危害
参考答案：C
从基本方向线的北端顺时针量至某一直线方向的角度，称为该直线的（）。
— I called you last night but no one answered the phone.
— I ______ dinner with my friends in the restaurant. [ ]
A. have
B. had
C. was having
D. have had
