______ by the beautiful scenery, I forgot to go back home in time.

A．Impressing

B．To be impressed

C．Having impressed

D．Impressed

计算题：有两台同步发电机作准同期并列，由整步表可以看到表针转动均匀，其转动一周的时间为5S，假设断路器的合闸时间为0.2S，求应在整步表同期点前多大角度发出合闸脉冲。