He got tired _________ over work.
He got tired _________ over work.
Explanation
He got tired because of over work.
Because: کسی وجہ کو ظاہر کرتا ہے
Because is a conjunction.
He got tired because of over work.
Because: کسی وجہ کو ظاہر کرتا ہے
Because is a conjunction.