一个直角三角板上有( )个直角,有( )个锐角。
1,2
Recent studies have discovered that fathers uniquely contribute to the development of their children, _____ in low income families.
A.specially
B.definitely
C.specifically
D.particularly
通信子网由 【3】 、通信线路与其他通信设备组成。完成网络数据传输转发等通信处理任务。