Well, for one thing, he's my sister's boyfriend. Ann talks about Jack all the time.
首先,他是我妹妹的男朋友。安整天就是杰克长杰克短的。
but that was precisely the idea adopted in some of the early instruments (seismometers) for recording earthquake waves.
但是早期记录地震波的仪器(测震仪)正是采用了这种思路。