a waste of time什么意思?高手进

问题描述:

a waste of time什么意思?高手进
making notes in class is often a waste of time.这什么意思啊?要么就making notes in class waste time.干嘛要用is?用a又是干什么的,难道可数?waste 后面加of 是干什么?

做课堂笔记,常常是浪费时间
is是be动词,a waste of time这个是固定用法.必须有介词Of