The noise of something________on the floor could be heart clearly in the quiet night.
A.being dragged
B.dragged
为什么选择A？而不选择B？
谢谢！

being dragged 是现在分词的被动式，它作定语的意思是“正在被拖的”；dragged是过去分词，作定语时可以理解为“先前被拖的”或“通常被拖的”。因此只能选A。The noise of something being dragged on the floor could be heard clearly in the quiet night. 可翻译为：在地板上拖过的东西发出的声音,在静静的夜里可以很清楚地听到.
另请看几个例子：
the problem being discussed now:现在正在讨论的问题；
the problem discussed yesterday:昨天讨论的问题；
the problem discussed every day:每天讨论的问题；
The teacher being asked questions is Miss Liu.有人在问她问题的这位老师是刘老师。
The teacher asked an odd question by his students last Friday is here.上周五被学生问了个怪问题的老师就在这。
He is a teacher respected by many people.他是一位受很多人尊敬的老师。