underream扩大: expansion; amplify; upstep; ...孔: hole; opening; aperture底: bottom; base孔底扩大器: underreamer钻孔底扩大: hole springing下载手机词典可随时随地查词查翻译关注微信公众号:chachacidian,回复:扩大孔底,即可在微信中查询翻译