Koo tsho uas muaj qhov rooj tsim nyog yog ib qhov khoom siv tshwj xeeb uas siv hauv tsev kho mob thiab hauv cheeb tsam los ua kom sov lossis kom nguam rau ib qhov rooj tshuaj. Qhov no yog ib qhov tseem ceeb rau ntau yam kev sim, kev test lossis kev ua haujlwm uas xav tau ib qhov rooj tshuaj zoo ib yam. ZONWON tsim cov khoom siv zoo VT2/VT4/VT6 Thov Tshuaj Ntuj Ci Zog uas yooj yim rau kev siv thiab pab cov neeg tso cai thiab cov neeg tsim khoom kom tau lwm qhov tseem ceeb. Cov khaub ncawg no muaj nyob hauv ntau yam qhov siv, ib qho ntawm lawv yog nyob hauv qhov siv ntawm kev xav txog qhov tseem ceeb, kev xav txog qhov tseem ceeb, thiab kev tsim khoom rau qhov tseem ceeb. Los ntawm kev tswj qhov cua ntawm dej kom zoo ib yam, lawv pab ua rau kev xav txog thiab kev ua haujlwm yuav tau raws li qhov tseem ceeb.