नए पदार्थ : जिराल्ड लीच द्वारा हिंदी पीडीऍफ़ पुस्तक – सामाजिक | Naye Padarth : by Gerald Leach Hindi PDF Book – Social (Samajik)
Pustak Ka Vivaran : Kuchh Varsh Pahale tak Manushy har cheej Padarthon se karate the jo bhoomi se upalabdh ho sakati thee. Unhen Dhatu aur koyala tatha tel Jameen se khad kar prapt hote the. Unhen Pedon Lakadi aur kapade banane ke liye oon, phar aur silk jaise padarth janavaron prapt hote the. Unhen har Cheej Prakrti se prapt hoti thee. Aur Aavashkayata ke liye kaphi Matra mein Prapt hoti thee. Usake bad do baten huyi. Vaigyanikon ne aisee Ajad kee jo unhen………..
Description about eBook : Until a few years ago, humans used to do everything that could be available from the land. They received metals and coal and oil from the ground. They used to get animals like wool, fur and silk to make trees, wood and clothes. He got everything from nature. And a considerable amount was obtained for necessity. Two things happened after that. Scientists invented them ………..
