It's too late now. I think the shop is _______.
A:open
B:closed
C:opens
D:closes
“政启开元,治宏贞观”称赞的帝王是( )
如图是研究“滑动摩擦力”的实验。
电影院的墙壁往往做成凹凸不平的,这是为了( )