Caver john pollack staged his first expedition to the site in 2006 .
洞穴专家johnpollack在2006年时对此地进行了第一次探险。
Discuss the characteristics and the application of nc caver , and its structure and main functions .
讨论了数控雕刻机的特点与应用,阐述了雕刻机的控制原理、组成以及主要功能。
An expedition in february 2008 , co-led by veteran caver john pollack , comprehensively mapped and photographed the 5.9-mile ( 9.5-kilometer ) length of the little-known cavern for the first time .
