Enclosures for protection against ionizing radiation Lead shielding units for 150 mm, 200 mm and 250 mm thick walls Part 1: Chevron units of 150 mm and 200 mm thickness???是什么意思_Enclosures for protection against ionizing radiation Lead shielding units for 150 mm, 200 mm and 250 mm thick walls Part 1: Chevron units of 150 mm and 200 mm thickness???在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句