he left his home as if going to work,so as not to arouse his parents' suspicion.so as not to arouse his parents' suspicion.在句中是什么成分?

he left his home as if going to work,so as not to arouse his parents' suspicion.so as not to arouse his parents' suspicion.在句中是什么成分?
he left his home as if going to work,so as not to arouse his parents' suspicion.
so as not to arouse his parents' suspicion.在句中是什么成分?

he left his home as if going to work,so as not to arouse his parents' suspicion.so as not to arouse his parents' suspicion.在句中是什么成分?
原因状语