“七国之乱”、“安史之乱”与“藩镇割据”发生的相同原因是 [ ]

A、中央政府统治腐朽

B、地方势力膨胀的结果

C、皇帝荒废朝政的结果

D、朝廷兵力空虚

At the World Literacy Center, an organization that works to help people read, the helpers work hard, enabling them to successfully reach their goals..

A．assistants

B．volunteers

C．part-timers

D．amateurs