单词	revival sunspot group
释义	revival sunspot group 重现黑子群
随便看	main shaft of hydroturbine main shaft of steam turbine mainshaft oil baffle mainshaft overdrive gear main shaft overdrive gear mainshaft overdrive gear bushing mainshaft overdriver gear main shaft packing mainshaft pilot bearing mainshaft rear bearing mainshaft rear bearing oil seal mainshaft roller bearing main shaft seal main-shaft seal main shaft sealing main shaft sinkage mainshaft sleeve main shaft sleeve mainshaft sleeve clamp lever mainshaft sliding gear mainshaft snap ring main shaft speed mainshaft speed gear retainer ring mainshaft speed gear sleeve main shaft support