如图,在菱形ABCD中,∠B=60°,AB=1,延长AD到点E,使DE=AD,延长CD到点F,使DF=CD,连接AC、CE、EF、AF,则下列描述正确的是( )
海峡是海洋运输的重要通道。图中甲、乙、丙、丁中代表马六甲海峡的是( )
When our teacher came into the classroom, we stopped ____ (talk).