Which component of a lichen is heterotrophic?

How many geometrical isomers are possible for the complex $[Mab(AB)_2]^{\pm n}$?

Blood must pass through the ........ to reach the left side of the heart.

$A$ point charge $+q$ is placed at the centre of a cube of side $L$. The electric flux emerging from the cube is

$A$ parallel plate capacitor with air between the plates has a capacitance of $9 \ pF$. The separation between its plates is $d$. The space between the plates is now filled with two dielectrics. One of the dielectrics has a dielectric constant $K_1 = 6$ and thickness $\frac{d}{3}$,while the other has a dielectric constant $K_2 = 12$ and thickness $\frac{2d}{3}$. The new capacitance of the capacitor is ........ $pF$.

The number of oxygen atoms bonded to one phosphorous atom in $P_4O_6$ is