self-supporting wall自: self; oneself; one's own支: branch; offshoot护: protect; guard; shield井壁: wall of a well砖石支护井筒: masonry shaft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:自支护井壁，即可在微信中查询翻译
