A:①
B:①②
C:①②③
D:①②③④
两个阻值相等的电阻串联后的等效电阻是40Ω,那么它们并联后的等效电阻是____ Ω.
It is five years _____his father worked here.
关于细胞全能性的理解不确切的是( )
观察数轴图列算式。
____
_______ you have visited the Great Wall, you can’t imagine how great it is.