Can you take a stainless cane with 3 mm in diameter and drill a hole of 2 mm alongside the cane at the depth of 3 cm?
你能否用一根直径为3 mm的不锈钢棒，在旁边钻出一个直径为2 mm、深度为3 cm的孔？
2
Hu Yanhuai's novel "the Hole Fire" explores the human nature in depth through the story of treasure hunt in an ancient mine.
胡燕怀的小说《洞火》借助于一个古矿井寻宝的故事，对人性的奥秘进行了深入的探讨。
3
By varying the groove spacing, the diameter of the single or double diameter hole, and the rear air cavity depth and content, one can obtain absorption over a wide variety of frequencies.