Dear teachers,<br/><br/>I am doing an exercise with this sentence:<br/><br/>10) The factory let go of many its employees because it had automated <b>so </b>operation.<br/><br/><br/><br/>I don't understand the meaning and grammar function of "SO" here. <br/><br/><br/>Could you please help me clarify this?<br/><br/>Thank you in advance