The technique used to make numerous copies of a specific segment of $DNA$ quickly and accurately is

Which one of the following is used in the preparation of cellulose nitrate?

Curie temperature is the temperature above which:

$A$ plane mirror is placed at the bottom of a tank containing a liquid of refractive index $\mu$. $P$ is a small object at a height $h$ above the mirror. An observer $O$,vertically above $P$ outside the liquid,sees $P$ and its image in the mirror. The apparent distance between these two will be

The intercepts on the $x$-axis made by the tangents to the curve $y = \int_0^x |t| dt, x \in R$ which are parallel to the line $y = 2x$ are equal to:

If $\frac{1}{x(x^2 + 1)} = \frac{A}{x} + \frac{Bx + C}{x^2 + 1}$,then $(A, B, C) = $