Cam khwb cia hlau lauj kaub yog lub feem ntau nrov ua noj lauj kaub nyob rau hauv Tuam Tshoj vim nws lub zog siab, hlau replenishment, kev lag luam thiab practicality.Txawm li cas los xij, cam khwb cia hlau lauj kaub tam sim no nyob rau hauv kev ua lag luam yog tag nrho cov cam khwb cia hlau los yog siv dua hlau.Cov khoom tseem ceeb ntawm cam khwb cia hlau: carbon (C) = 2.0 txog 4.5%, silicon (...
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