Lub iav helical rau cov iav helical hauv cov tshuab nqa khoom yog ib qho tseem ceeb uas ua kom muaj kev sib kis hluav taws xob zoo thiab ua haujlwm tau zoo. Nws txoj kev tsim helical tshwj xeeb txo cov suab nrov thiab kev co, txhim kho kev ua tau zoo tag nrho. Lub iav teeb tsa kev tsim kho kom raug ua rau muaj kev sib koom ua ke zoo, muab lub peev xwm thauj khoom ruaj khov. Haum rau ntau yam kev siv nqa khoom, nws lav qhov kev ntseeg tau thiab kev ua haujlwm ntev, ua rau nws yog ib feem tseem ceeb ntawm cov tshuab nqa khoom niaj hnub.
Sab saum toj kaum lub tuam txhab hauv Suav teb, nruab nrog 1200 tus neeg ua haujlwm, tau txais tag nrho 31 qhov kev tsim kho tshiab thiab 9 daim ntawv pov thawj. Cov khoom siv tsim khoom siab heev, cov khoom siv kho cua sov, cov khoom siv tshuaj xyuas.