词汇	iron notch drill
释义	iron notch drill 开铁口机
随便看	principal industry principal inertia axis principal ingredient principal ingredient analysis Principal injury principal IN-rings principal installments principal items principalities principalities of andorra principal instalments principal interest principal in the first degree principal in the second degree principal invariant principal invariant of tensor principal inverse function principal investigation principal investigator principal investigator responsibility system principal investigators Principal investigator systems principal ion principalis principal island