The tunnelphenomenon "is caused by the eye's susceptibility to the low blood flow that occurs with fainting or cardiac arrest," he said.
隧道现象“是由眼睛的易感性低血流量，与发生昏厥或心脏骤停造成的，”他说。
2
Karst is a process and result of groundwater geologic function and it is one of bad geological phenomenon facing tunnel construction.
岩溶是地下水地质作用的过程和结果，是隧道建设面临的不良地质现象之一。
3
During tunnel construction, it often produces the abrupt phenomenon of gushing because of complicated geology term, through the engineering construction result in the serious difficulty.