《墨子·62章 备穴》
隧道中装置环索供上下牵引，每条隧道安装两种这样的环索。
穴中为环利率，穴二。
The tunnel was equipped with loops for pulling up and down, and each tunnel was equipped with two such loops.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 穴中为环利率，穴二。 [/INST] The tunnel was equipped with loops for pulling up and down, and each tunnel was equipped with two such loops.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 穴中为环利率，穴二。
user
The tunnel was equipped with loops for pulling up and down, and each tunnel was equipped with two such loops.
assistant