There is also a 50-metre-long swiming pool 同义句

首先,楼主你的swimming打错了,要双写m的。以下是答案：1。There is also a swimming pool ,which is 50-metre-long 。2。There is also a swmming pool whose(of which) length is 50 meters。这2个句子都是定语从句,第一个是非限制性定语从句,起补充说明的作用,去掉后面这个从句前面的句子依旧成立；第二个是限制性的定语从句,起先行词限制作用。希望我的回答能帮到你