— I hear the famous singer Xu Song may come to Weifang next month.

— Really? _______ he comes, my younger sister will be very excited.

A．If

B．Until

C．Unless

D．Before

优秀代维办事处要求办事处内部有良好的（）（定期召开班组和质量分析等会议），开展节假日（）活动。