1. Ua ntej thiab tom qab inflating lub hnab nqus tsev vacuum, ceev faj tsis txhob cia nws khawb los ntawm cov khoom ntse. Nws yog qhov zoo tshaj plaws los khiav nws ntawm lub txaj lossis ntawm lub rooj huv si. Nyob rau tib lub sijhawm, koj yuav tsum tau them sai sai rau seb puas muaj cov khoom ntse hauv qhov chaw khaws cia kom ntseeg tau tias kev ncaj ncees ntawm lub hnab. Qhov no yog qhov yuav tsum tau yooj yim tshaj plaws, thiab nws kuj yog qhov yuam kev tshaj plaws uas txhua tus ua. Qhov tseem ceeb tshaj plaws yog qhov yooj yim tsis quav ntsej. Kuv tau pom ntau zaus tias cov khoom ntim los ntawm cov neeg siv khoom tau punctured lub hnab ntim khoom. Kuv yeej hais tsis tau lus.
2. Khaws cov khoom kom deb ntawm lub hnab ntim khoom. Sim mus yuav ib lub hnab uas loj txaus. Ntawm chav kawm, tsis txhob blindly caum qhov loj. Tom qab tag nrho, lub hnab loj dua, nws yuav kim dua.