在风水观念中，宅、村、城镇基址选择的基本原则和基本格局是（），背山面水。
参考答案：负阴抱阳
David threatened_____ his neighbour to the police if the damages were not paid.
A．to be reported
B．reporting
C．to report
D．having reported
三角形连接的负载，线电流是相电流的1.73倍。
