A:a点所示溶液中c(Na+)>c(A﹣)>c(H+)>c(HA)
B:a、b两点所示溶液中水的电离程度相同
C:pH=7时,c(Na+)=c(A﹣)+c(HA)
D:b点所示溶液中c(A﹣)>c(HA)
已知(a+b)2=16,ab=4,求a2+b2与(a-b)2的值.
—I think teenagers should be allowed to make their own decisions when they have problems at school.
—_______. They're not calm enough, after all.
命题p:∃α∈R,sinπ-α=cosα; 命题q:∀m>0,双曲线x2m2-y2m2=1的离心率为2,则下面结论正确的是( )
在“测定小灯泡的电功率”的实验中,小明选取了一个标有“2.5V”的小灯泡和必要的实验器材,连接的实物电路如甲图所示: