Large amounts of food ______ wasted in our school everyday, but the poor in many countries ______ no access to drinking water.
A:is; has
B:are; have
C:is; have
D:are; has
下图中A,B,C,D四地位于同一纬度,其昼夜温差最小的是( )
下列方程中,是一元二次方程的是( )