如图4所示的电路中,当滑片P向左移动时,电压表和电流表的示数变化情况是图4
A:电流表示数增大,电压表示数不变
B:电流表示数增大,电压表示数增大
C:电流表示数不变,电压表示数减小
D:电流表示数减小,电压表示数减小
A: Welcome to my birthday party, Billy!
B: Happy Birthday to you, Amy! This is for you·
A: Oh, a beautiful doll! It's blue. I like it. Thank you!
B: Who's that women in the long blue skirt?
A: She's my aunt. Her name's Wendy.
B: What does she do?
A: She's a teacher.
下列属于复杂反射(条件反射)的是( )
已知函数f(x)=3x-3,x>0-x2-4x-2,x≤0若函数g(x)=f(x)﹣2m有3个零点,则实数m的取值范围是( )