–David, is that _____ English teacher?
--Yes, he is ___. He is very caring.
A:yours; ours
B:your; our
C:yours; our
D:your; ours
长江、黄河源头所在的省区是( )
设f(x)=3x+3x-8,用二分法求方程3x+3x-8=0在x∈1,2内近似解的过程中得f(1)<0,f(1.5)>=,f(1.25)<0,则方程的根落在区间( )