vol英文：volume的缩写，也就是第几章的意思。volume：n.体积;容积;容量;量;额;音量;响度；复数： volumes

相关介绍：

Can you turn the volume up a bit?

你能把音量开大点儿吗？

This work has grown in volume recently.

这项工作的量最近增加了。

New roads are being built to cope with the increased volume of traffic.

正在修建新的`道路以应付增加了的交通量。

The number of accidents is proportionate to the increased volume of traffic.

交通事故的数字与交通量的增长成正比。