— Have you decided ______ with her?
— ______.
A:go; Certainly
B:to go; Not yet
C:going; Have already
D:to go; No yet
如图,将矩形ABCD绕点A顺时针旋转90o后,得到矩形AB’C’D’,若CD=8,AD=6,连接CC’,那么CC’的长是( )
____(按先左后右、先上后下的顺序填写)
化学与生活密切相关,下列生活中常见物质的俗名与化学式相对应的是( )
抛物线y=4x2的焦点坐标是( )
用可溶性钡盐检验SO42﹣离子的存在时,先在待测溶液中加入盐酸,其作用是( )