B??c 2: Simply click và s?n ph?m mu?n mua, màn hình hi?n th? ra pop up v?i các l?a ch?n sauCold finger-A lengthy copper rod extending alongside The within on the electron column. When its reservoir is stored filled with liquid nitrogen, the rod appeals to contaminants That may or else degrade the chamber's vacuum.– T?o s? c?nh tranh cho doanh