民航的运输飞行主要有______形式。
A．班期飞行
B．包机飞行
C．加班飞行
D．不定期航班飞行
参考答案：A,B,C
The retired man donated (捐赠) most of his savings to the school damaged by the earthquake in
Yushu, ______ the students to return to their classrooms. [ ]
A. enabling
B. having enabled
C. to enable
D. to have enabled
二手房买卖成交正式签订成交合同后，经纪企业应协助客户办妥房产( )手续。
A．变更登记
B．转移登记
C．产权登记
D．他项登记
