Qhov kub thiab txias yog ib qho tseem ceeb tshaj plaws uas ua rau cov hlau nplaum muaj zog, nyob rau hauv qhov kub thiab txias ua rau cov yam ntxwv ntawm cov hlau nplaum muaj zog nrog cov hlau nplaum zoo li yuav ua rau muaj zog thiab tsis muaj zog, uas ua rau lub zog hlau nplaum hlau nplaum yog r ...
Nyeem ntxiv