Which soluble molecules are included in the human immune system?

Which chemical must be applied to the roots to keep the leaves of a plant green?

$\int_0^{\frac{\pi}{4}} \frac{\cos ^2 x}{\cos ^2 x+4 \sin ^2 x} d x=$

$A$ gaseous mixture contains $CH_4$ and $C_2H_6$ in equimolecular proportion. The weight of $2.24 \ L$ of this mixture at $NTP$ is ............ $g$.

The $24$ hour (diurnal) rhythm of our body,such as the sleep-wake cycle,is regulated by the hormone:

Among the following compounds $(I-III)$,the correct order of reactivity towards electrophilic substitution is: