题目

Let me _______ your photo .            A．look                        B．have a look             C．have a look at          D．have look                                   答案：C19．光控开关，夜晚自动闭台，白天断开；声控开关，有声音时自动闭合，安静时断开．请把图连接成声光控楼道节能照明电路．