I see. By the way, how many people are working in your factory now?
哦,我知道了。顺便问一下,现在贵厂有多少在职职工?
The second marks the arrival of transverse vibrations which travel more slowly and arrive several minutes after the first.
然后记录下的是横向波的到达,横向波比纵向波传播得慢,在纵向波到达几分钟后才能到达。