用一种正多边形铺地，使它铺成平整无隙的图案，顶点处最多能用正多边形的块数是[ ]
A.5
B.6
C.7
D.8
答案：B
在树林漫步时，我们发现树叶间的缝隙是不规则的，但透过缝隙的阳光在地面上呈现一个个的亮圆斑．亮圆斑是______，这种现象叫______．
You haven't seen your old friend for years. What would you first say if you met each other?[ ]
A. How you've changed!
B. How do you do?
C. Where did you go?
D. You missed me?
