As soon as he entered the room,the girl caught sight of the flowers ( )by her aunt.

问题描述:

As soon as he entered the room,the girl caught sight of the flowers ( )by her aunt.
1.buying 2.being bought 3.were bought 4.bought
原因写详细点(有什么语法或词组之类的),劳驾各位了.我还有很多问题没人答,麻烦高手也去看看,

As soon as he entered the room,the girl caught sight of the flowers ( )by her aunt.1.buying 2.being bought 3.were bought 4.bought 4.bought定语从句,省略which were