He usually comes to school ________ the school bus, not ________ bike.
A:on; on
B:by; by
C:on; by
D:by; on
《申报》“时评”栏目曾评述说:“今之时局,略似春秋战国时期之分裂。中央政府之对于各省,犹东周之对于诸侯也。南北相攻,皖直交斗,滇蜀不靖,犹诸侯相侵伐也。”这一时局出现在( )