Xyoo 1960 thiab 1970, tsis muaj cov ntsia hlau muaj zog heev, thiab cov txheej txheem vuam tsis tau nce qib zoo li tam sim no. Yog li ntawd, ntau lub tsev hlau tau txuas nrog rivets, uas qee zaum tuaj yeem pom thaum saib cov yeeb yaj kiab qub. Nws yuav luag yog ib qho khoom qub.
Cov rivets rub txhuas lossis hlau yog siv rau kev xauv cov hlau thaum siv ua lub tsev kaw, thiab tsis tuaj yeem siv rau hauv lub tsev. Raws li seb lub tsev kaw hlau puas yog lub tsev hlau lossis tsis yog, tsawg kawg cov kws tshaj lij hauv lub sijhawm ntawd tau ua tib zoo saib xyuas rub rivets.
Lub sijhawm tshaj tawm: Lub Kaum Hli-20-2021