I've been using telegram for about 4 months, and in that time I have joined several seemingly "Legit" telegram groups and participated in many airdrops, but almost 90% of them asked me to send eth as a gas fee to a wallet in order to receive my airdrop, I have been told never to send eth in order to get an airdrop because it's a scam and a real airdrop wouldn't have you send eth for a gas fee, is this correct? 

   Are all these airdrops on telegram scams? And where are the real airdrop groups? Please help, I'm not wealthy and can not afford to send eth especially at the current fees just to lose my money! Any help will be much appreciated!!