mass词义知多少
1. mass常作可数名词，意为“团；块；堆”；用作不可数名词，指物理术语中的“质量”。如：
A mass of rock had fallen from the cliff and now blocked the road.
一大块岩石从悬崖上掉了下来，堵塞了道路。
A liter of gas has less mass than a liter of water.
一升汽油的质量比一升水的质量小。
2. a mass of (也可用masses of)表示“大量；大批”，既可修饰可数名词，也可修饰不可数名词。如：
I’ve masses of work to do.
我有许多的工作要做。
There were a mass of children in the yard. 院子里有一大群孩子。
