已知函数f(x)=ax2+2x是奇函数,则实数a=______.
由奇函数定义有f(-x)=-f(x),
则f(-1)=a-2=-f(1)=-(a+2),
解得a=0.
I'm so hungry. Please give me ______ to eat
A.three bread
B.three pieces of bread
C.three pieces of breads
D.three piece of bread
电路处于开路状态时,电流值()。
A.最大
B.最小
C.为0
D.无穷大