下列选项中（）是九阶段实施方法中的最后一个阶段。
A.切换阶段
B.新系统支持阶段
C.会议室导航阶段
D.二次开发阶段
参考答案：B
Born into a family with three brothers and two sisters, Peter was to value the sense of sharing. [ ]
A. brought up
B. turned down
C. looked after
D. held back
一钮控制方式指的是
A．人工调整管电压
B．人工调整电容电流
C．人工调整电源电压
D．人工调整曝光时间
E．人工调整接地电阻
