Since we are doing an informal proof, I will not name the axioms we are using nor will I attempt to prove the intermediate theorems used to make the proof work.
QB type explosion-proof hook bridge crane work level is intermediate.
QB型防爆吊钩桥式起重机工作级别为中级。
3
The packaging film (10) of the bag body (19) has a moisture-proof layer (12) composed of an aluminum foil and an intermediate layer (13) composed of a drawn nylon.