如图1,是一个正方体的展开图,小正方体从图2所示的位置依次翻滚到第1格、第2格、第3格,这时小正方体朝上面的字是( )
A:真
B:精
C:彩
D:届
The chief engineer of the high-speed railway ________ Shanghai to Beijing always devotes most of his time ________ his work.
下列说法中正确的是( )
一个正多边的内角和是外角和的3倍,这个正多边形的边数是( )