快速、高效是（）的特点。
A.即时通讯
B.电子邮件
C.手机QQ
D.电话客户
参考答案：A
若∠AOB=60°，OC平分∠AOB，则∠AOC=______度．
The mayor of Zhuanghe City was ordered to resign because of his refusal to ________ when more than 1000 villagers got down on their knees before the city government office building, begging for his help.
A．break up
B．link up
C．fill up
D．show up
