1. Khaws ib qho chaw ua haujlwm zoo
2. Tsis txhob hnav cov hnab looj tes hnab looj tes thaum siv vuam siv. Vim tias kub npaum li cas thaum lub vuam, cov hnab looj tes rub tau yooj yim los ntawm kev kub siab.
3. Thaum lub plhaub tsis muaj steel hlau txiav tawm, cov hlau phom tsis xeb yuav tsum tau tsiv mus rau qhov chaw tshwj xeeb rau kev txiav. Nws yog nruj me ntsis txwv txiav kom txiav cov khoom siv ncaj qha rau ntawm cov khoom tsis muaj steel.
4. Cov hlau uas tsis muaj lub plhaub tais diav yuav tsum raug tsim tawm hauv kev ywj siab, kaw qhov kev tuav pov hwm los yog kev cog khoom tshwj xeeb thiab yuav tsum muab cais tawm ntawm carbon cov khoom.
5. Thaum siv kauj vuam siv fais fab, yuav tsum muaj ib daim txiag tsho ntawm 100 hli rau ntawm ob sab ntawm lub pob qij txhawm rau ua kom tshem tawm cov phom tawm.