For some reason, some designers love to version their theme design into sub level folders (ie. domain.com/v2
因为几个原因，有些设计师喜欢以把主题设计放进不同子目录（ie. domain.com/v2, v3, v4）的方式进行版本划分，并重定向到新的文件夹。
"We still have to test how gravity behaves at a sub-atomic, quantum level," he said.
“我们仍然需要测试重力在亚原子，量子级别的影响，”他说。
Which categories are the top-level categories, and which are sub-categories?
哪些类别是顶级类别，哪些是子类别？
Sub-level caving is an efficient and safe mining method.
无底柱分段崩落采矿法是一种高效安全的采矿法。
Each type can be divided into sub-series or son-series with the difference of study level.
每一类型都具有一定的层次，依研究程度的不同可以划分到亚系列和(或)子系列。
A math model of the sub structure level is built to calculate the work cycle.
为设计计算工作循环，建立了该模型结构子层的数学模型。
Call tile map loaded in the generated site, sub-level detail display.
说明：调用瓦片图加载在生成的网站中，分级别详细显示。
The control of water level and combustion sub-system is realized.
实现对水位和燃烧子系统的控制。
The measure sub-element , the phase-comparator , and the power level are introduced.
对检测环节、鉴相器、功率级做了介绍；
The measure sub-element , the phase-comparator , and the power level are introduced.
对检测环节、鉴相器、功率级做了介绍；
应用推荐