Tawm tsam lub backdrop ntawm lub ntiaj teb ntim kev lag luam nrawm nrawm, tab sis kuj tseem ua tau zoo ntawm kev lag luam ib puag ncig, tab sis kuj tseem ua haujlwm ntawm kev ua haujlwm niaj hnub no.
Los ntawm qhov kev pom ntawm cov khoom siv, cov ntsiab lus tseem ceeb ntawm cov ntawv txheej txheem ntawm cov khoom siv cov khoom siv ntawm cov khoom siv 1 {. 5 zaug ntawm cov yas ntim khoom xws li cov khoom lag luam kas fes zoo li cov khoom lag luam ua ntej rau cov zaub mov, tshuaj lom neeg thiab lwm yam khoom siv thiab lwm yam khoom siv.
Cov Txheej Txheem Ib puag ncig yog qhov tseem ceeb ntawm lub hnab ntim khoom, kraft ntawv me me thaum muaj kev sib cais yog li 30% Ntim, uas yog heev sib xws nrog qhov yuav tsum tau ua ntawm "rov qab los ntawm cov ntawv tshaj tawm" (PPWRAFTB
Kev Siv Tshuab thev naus laus zis rau kraft ntawv cov khoom lag luam, thiab muaj peev xwm ua tiav cov khoom siv hluav taws xob, thiab muaj peev xwm ua tiav cov khoom siv hluav taws xob, thiab muaj peev xwm ua tiav cov khoom siv hluav taws xob tshwj xeeb thiab cov tswj cov suab nrov hauv qab no 0 {. 5 grams tauj ib square Meter thaum ua kom pom kev zoo nkauj, uas tau ua raws li cov qauv kev luam ntawv thoob ntiaj teb.
Raws li lub thoob ntiaj teb kev lag luam tseem them ntau dua rau cov khoom siv tiv thaiv cov pa roj carbon monoxide card