Which one of the following cannot form an amphoteric oxide?

Which of the following has the highest electrode potential?

The angle between the lines $ab(x^2 - y^2) + (a^2 - b^2)xy = 0$ is

At a given instant of time,the position vector of a particle moving in a circle with a velocity $\vec{v} = 3 \hat{i} - 4 \hat{j} + 5 \hat{k}$ is $\vec{r} = \hat{i} + 9 \hat{j} - 8 \hat{k}$. Its angular velocity $\vec{\omega}$ at that time is:

If $P(1, 2)$,$Q(4, 6)$,$R(5, 7)$,and $S(a, b)$ are the vertices of a parallelogram $PQRS$,then:

Which pair of the following belongs to Basidiomycetes?