石臼是人们最早加工谷物的工具之一。

The stone mortar is one of the earliest tools for processing grains.

本文对石臼港区强风化花岗岩的变形和破坏的力学机制做了全面地分析论证。

This paper has made a comprehensive analysis and demonstration to the mechanism of deformation and destruction of granite strong weathering zone in Shiju Port.

方法采用随机分层整群抽样方法，对日照市石臼街道常住人群进行面访式问卷调查。

Methods A survey on prevalence of FD in communities of Shijiu Neighborhood, Rizhao was conducted by using a stratified, randomized cluster-sampling method.