A:观察法
B:测量法
C:实验法
D:调查法
There was a time ______ I thought my dad didn't know a thing about being a good father.
如图,____ 与∠C是直线BC与____ 被直线AC所截的同位角,____ 与____ 是直线AB与AC被直线DE所截的内错角,____ 与∠A是直线AB与BC被直线____ 所截的同旁内角.