Boric acid is $NOT$ used in which of the following?

The solution of the differential equation $\frac{dy}{dx} = \frac{x - y + 3}{2(x - y) + 5}$ is

Which of the following substances is the most acidic?

Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is held at a temperature of $100^{\circ} C$,while the other one is kept at $0^{\circ} C$. If the two are brought into contact,then assuming no heat loss to the environment,the final temperature that they will reach is

Which part of the human brain is concerned with the regulation of body temperature?

The solution of $\tan y \frac{dy}{dx} = \sin(x+y) + \sin(x-y)$ is