প্রকৃতিতে প্রাপ্ত সবচেয়ে কঠিন পদার্থ কোনটি?

PSC DOL Assistant Director BCS 23rd BCS Preli - 2001 BPDB SA - 2012 PWD SAE (Civil) - 2011 MoFA Cypher Officer - 2012 Prisons Jail Superintendent - 2013 BJS 9th BJS Preli - 2014 PTD Accounts Officer - 2003 DNS Assistant Director - 2009 Primary Teacher Primary Assistant Teacher - 2010 BMET Assistant Director - 2001 DOL Assistant Director - 2005 CD Cipher Officer - 2005 DOE Research Officer - 2006 BPS Assistant Director - 2006 DSS Social Service Officer - 2010 Krishi Bank BKB Data Entry Operator - 2012 Petrobangla BGDCL – Assistant Officer - 2006 IBBL IBBL PO - 2013 IBBL Officer - 2013 ATEO ATEO - 2005 PPA – Assistant Sub-Inspector - 2018 MODMR – Auditor - 2019 TGTDCL – Technician/Sales Assistant - 2023 PGCB – Technical/Office Assistant - 2024 IBBL Officer - 2005 IBBL Officer - 2009 সাধারণ বিজ্ঞান 2005 কার্বন (Carbon - C)