A line used as both sterile and maintaining line
agonic line {agonic line of no declination}
Dual purpose line with nucleic male sterile line
Fault Cutoff Line Allan Line
Male sterility line and maintainer line
velocity line of arc line short band
bailer
捞砂
委托
吊桶
委托人
捞砂筒
排水吊桶
泥浆泵
水斗
抽泥筒
舀水勺
戽斗
汲筒天车
簧头
铲
汲筒
取砂器
水瓢
颚舟叶
bailer method of cementing