Which taxonomic category is written first when writing the scientific name of an organism?

$\int_{-\pi / 2}^{\pi / 2} \sin |x| \, dx$ is equal to

If $x$ is small,so that $x^2$ and higher powers can be neglected,then the approximate value for $\frac{(1-2 x)^{-1}(1-3 x)^{-2}}{(1-4 x)^{-3}}$ is

Consider the following statements for $X = \dot{C}H_3$ and $Y = \dot{C}F_3$:
$(I)$ When $X$ dimerises,the bond angle decreases.
$(II)$ When $X$ dimerises,the bond angle increases.
$(III)$ In the $X-Y$ molecule,the $C-C$ bond length is less than that in the $Y-Y$ molecule.
$(IV)$ The bond angle in $X$ is greater than that in $Y$.

In the process of transcription,the sigma factor is important for:

If $\alpha$ and $\beta$ are the roots of the equation $ax^2+bx+c=0$ and the equation having roots $\frac{1-\alpha}{\alpha}$ and $\frac{1-\beta}{\beta}$ is $px^2+qx+r=0$,then $r=$