Susceptibility to extinction is due to

If $ax^2+2hxy-2ay^2+3x+15y-9=0$ represents a pair of lines intersecting at $(1,1)$,then $ah=$

In the Victor-Meyer's test,the colours given by $1^o$,$2^o$ and $3^o$ alcohols are respectively:

If $\frac{x^3}{(2 x-1)(x+2)(x-3)} = A+\frac{B}{2 x-1}+\frac{C}{x+2}+\frac{D}{x-3}$,then $A$ is equal to

The first formed primary phloem is referred to as $A$. The later formed primary phloem is referred to as $B$.
Choose the correct combination of $A$ and $B$.

Which of the following is $NOT$ a part of the intratesticular genital duct system?