choleretic
发表于 2025-3-28 16:31:14
ouc. annually – extracted from the sap of the tree Hevea brasiliensis – and most of that went for making erasers. Indeed, it had been reported by the English minister and scientist Joseph Priestley (1733–1804) that pieces of rubber are well-suited to rub out (sic!) pencil marks. Even today there is
巨头
发表于 2025-3-28 20:47:30
http://reply.papertrans.cn/89/8820/881927/881927_42.png
饮料
发表于 2025-3-29 01:00:51
Supersymmetric Methods in Quantum and Statistical Physics
PAC
发表于 2025-3-29 04:59:59
10楼
Gene408
发表于 2025-3-29 10:05:02
10楼