—Don't _________, my children. Keep working hard and you will win the match.
—Thank you, Mr. Zhang. We'll try our best.
A:put up
B:call up
C:set up
D:give up
新疆的地形概括为“三山夹两盆”,其中位于两盆之间的山脉是( )
如图,一个四棱锥的底面为正方形,其三视图如图所示,则这个四棱锥的体积为( )
数列an的通项公式an=ncosnπ2,其前n项和为Sn,则S2013等于( )