旅客票价从（）起实行递远递减。
A.100km
B.101km
C.200km
D.201km
参考答案：D
Though ____money, his parents managed to send him to university.
A．lacked
B．lacking of
C．lacking
D．lacked in
执法人员和其他办案人员在什么情形下，应当回避？
