A.集箱的更換 B.鍋筒挖補(bǔ) C.受壓元件的補(bǔ)焊 D.主焊縫的補(bǔ)焊 E.管子脹接改焊接
A.5 B.8 C.10 D.15
A.1~2萬h B.2~3萬h C.3~4萬h D.4~5萬h