Which of the following ecosystem types has the highest annual net primary productivity?

$SO_{2}$ is a strong reducing agent; however,it can also act as an oxidising agent. Which of the following shows its oxidising nature?

Which of the following is a herbicide?

The overall goal of glycolysis,Krebs' cycle,and the electron transport system is the formation of

The bond dissociation energy of $B-F$ in $BF_3$ is $646 \ kJ \ mol^{-1}$ whereas that of $C-F$ in $CF_4$ is $515 \ kJ \ mol^{-1}$. The correct reason for higher $B-F$ bond dissociation energy as compared to that of $C-F$ is

The products formed in the reaction of phenol with $Br_2$ dissolved in $CS_2$ at $0^{\circ} C$ are