i have worked for this school for 1 year 为什麽用两个For

i have worked for this school for 1 year 为什麽用两个For I have worked in this school for three years.同义句改写 This is the school ( ) I have ever worked for 9 years. I have taught in this school for ong year(改为同义句） I have already bought this computer for two year._____ My son will soon take my place ,()I have worked for ten year Is this the school ( ) I have studied for three years? I have been [ ] this school for 4 years Ain Bat I have been__ this school for 10 years.(at/in) I have had this pair of shoes for a year.与I have bought this less than I have been in this city for less than a year.1 【 I know how _____ you have all worked for this test.