战国时期的商鞅变法在秦国确立了：[ ]
A、禅让制
B、土地私有制
C、王位世袭制
D、科举制
答案：B
Our special thanks to go thousands of volunteers, without ____tireless work, none of this would be possible.
A．which
B．whom
C．whose
D．that
铁路电报由（）接收。
A、电报所
B、用户
C、设备维护人员
D、送报员
