Parents find it difficult _______ with their teenage children.
A:talk
B:talked
C:talking
D:to talk
(Ⅰ)当a=1时,求不等式f(x)≥0的解集;
(Ⅱ)当x∈﹣1,1时,不等式f(x)<0恒成立,求实数a的取值范围.
秦始皇统一文字的标准字体是( )