正五边形的对称轴共有[ ]
A.2条
B.4条
C.5条
D.10条
答案:C
(2013·甘肃兰州、靖远名校高三模拟)Social practice is an opportunity for students to gain________better understanding of how________society operates.
A.the;the
B.the;/
C.a;/
D.the;a