A:与醋酸、浓硫酸共热发生酯化反应时,②键断裂
B:与金属钠反应时,①键断裂
C:与浓硫酸共热至170℃时,②、④键断裂
D:在加热和Ag催化下与O2反应时,①、③键断裂
____ ?
When playing football, Tom had his leg b____and was sent to a hospital.
《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( )