Which of the following substances leads to the inhibition of the central nervous system?

According to Robert May,the global species diversity is about ...................

Suppose the gravitational force varies inversely as the $n^{th}$ power of distance. Then the time period of a planet in circular orbit of radius $R$ around the sun will be proportional to

Let $f(x)=15-|x-10| ; x \in R$. Then,the set of all values of $x$,at which the function $g(x)=f(f(x))$ is not differentiable,is

In plants,which elements are most readily mobilized?

To what temperature should the hydrogen at $327^{\circ}C$ be cooled at constant pressure,so that the root mean square velocity of its molecules becomes half of its previous value? (in $^{\circ}C$)