How many major groups have recent researchers classified the plant kingdom into?

Temperate evergreen forests are found in

If $f: R \rightarrow R$ and $g: R \rightarrow R$ are defined by $f(x)=|x|$ and $g(x)=[x-3]$ for $x \in R$,then $\{g(f(x)):-\frac{8}{5} < x < \frac{8}{5}\}$ is equal to

If $(x-2)$ is a common factor of the expressions $x^2+ax+b$ and $x^2+cx+d$,then $\frac{b-d}{c-a}$ is equal to

When a cell is fully turgid,which of the following will be zero?

$A$ point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$ are at distances of $2 \ m$ and $3 \ m$ respectively from the source. The ratio of the intensities of the waves at $P$ and $Q$ is