Вот решения с использованием нефинитивных определительных придаточных предложений (non-defining relative clauses) и заданных слов:
The swimming pool, which is open every day from 9am to 5pm, is two metres deep.
My favourite gym, where I have been going for two years, is called Fitness Centre.
My sister, who took up ice skating when she was only six, has made it to this year’s national finals.
Sunday’s match, which ended in a draw, was the last one of this season.
I joined a Pilates course, which I like a lot.
Nadia Comăneci won her first gold medals in Montreal, where the 1976 Summer Olympics took place.
Если нужно более подробное разъяснение каждого варианта или дополнительные задания, с удовольствием помогу!