It can take as long as eight days to rig up rope ladders and to establish supply bases before a descent can be made into a very deep cave.是什么意思_It can take as long as eight days to rig up rope ladders and to establish supply bases before a descent can be made into a very deep cave.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句