Police were periodically patrolling the area.警察定时在这一地区巡逻。Police are patrolling the major approach roads to the stadium.警察正在通往运动场的主要道路上巡逻.I saw women patrolling the streets with rifles on their backs.我看到妇女背着枪在街上巡逻....
Now, use your pocketknife to touch the mica and see what will happen.现在你用小刀去触及岩石中的云母,看看会产生什么现象.It could not pass through material impervious to water such as mica.它不能通过云母这样的不透水的物质.To this class of substance belong mica, ...