伴随着生理发育,我们的心理也会不断发生变化,出现矛盾和困惑,导致我们出现矛盾心理的变化有( )
①自我意识不断增强 ②认知能力得到发展
③情感世界愈加丰富 ④说话声音发生变化
A:①②④
B:①③④
C:①②③
D:②③④
① How tall is it? ____ A. Zhang Yong.
② Who is the tallest boy? ____ B. Maybe 5 metres.
③ What size are your shoes?____ C. Forty yuan.
④ How much is your T-shirt? ____ D. Size 38
⑤ How old are you?____ E. I'm fifteen years old.
①4a+c<0;②m(am+b)+b>a(m≠﹣1);③关于x的一元二次方程ax2+(b﹣1)x+c=0没有实数根;④ak4+bk2<a(k2+1)2+b(k2+1)(k为常数).其中正确结论的个数是( )
根据材料,回答下列问题: