Which of the following is present in maximum amount in acid rain?

Curie temperature is the temperature above which:

Which of the following is the correct structure of $L$-glucose?

Persistent nucellus in the seed is known as

If $\sin ^{-1}\left(\frac{3}{x}\right)+\sin ^{-1}\left(\frac{4}{x}\right)=\frac{\pi}{2}$,then $x$ is equal to

The figure shows a system of logic gates. From the study of the truth table,it can be found that to produce a high output $(1)$ at $R$,we must have