?ây là m?t trong nh?ng ph??ng pháp in ?n Hello?n ??i nh?t Hello?n nay. Công ngh? Offset tuy?t v?i ??n m?c cho ra thành ph?m ??p nh?t v?i chi phí r? nh?t.Cold finger-A long copper rod extending together the inside from the electron column. When its reservoir is held crammed with liquid nitrogen, the rod attracts contaminants That may usually d