Which of the following pairs of organs consists only of endocrine glands?

Let $f(x)$ be a continuous and differentiable function for all real numbers such that $f(x + y) = f(x) - 3xy + f(y)$. If $\lim_{h \to 0} \frac{f(h)}{h} = 7$,then the value of $f'(x)$ is:

Vexillary aestivation is a characteristic feature of the family .........

The site of action of insulin is

The transformed equation of $x^2+6xy+8y^2=10$ when the axes are rotated through an angle $\frac{\pi}{4}$ is:

Let $P = \{\theta : \sin \theta - \cos \theta = \sqrt{2} \cos \theta\}$ and $Q = \{\theta : \sin \theta + \cos \theta = \sqrt{2} \sin \theta\}$ be two sets,then: