the school was a very difficult period of my life when i first met him.the school was a very difficult period of my life.i studied in the school for 2 years.the time was a very difficlt period of my life.i first met him at that time合并为定语从句全部4句合成一句吗？2句合一句the school was a very difficult period of my life when i studied in the school for 2 years.