i started to teach english three years ago

i have taught English for three years 再问： 我直到亲眼看到了那条河才意识到了保护河流的重要性。 i ____ ____ the ____ _____ _____ the rivers _____ i saw the river with _____ _____ ____。 there was a shoe factory near here in the past。 =there __ ___ ___ a shoe factory nere here。 再答： 分别是 didn't realise importance of protecting until my own eyes used to be