(Check the phone number from the directory; don't depend on a phone number given to you by the visitor, cross-check it all. Use a proper lock on doors and windows and fix them on doors and windows. दरवाज़े और खिडकियों पर अच्छे ताले फिट करें, और सदैव उनका उपयोग करें।
परिभाषा
check out conflicting sources; crosscheck facts, for example
मोबाइल