Which of the following components of cement is present in the highest amount?

Which of the following statements are correct?
$(i)$ In prokaryotic cells,a special membranous structure formed by the extension of the plasma membrane into the cell is known as polysome.
$(ii)$ The smooth endoplasmic reticulum is the major site for synthesis of glycoproteins.
$(iii)$ $RuBisCO$ is the most abundant protein in the whole biosphere.
$(iv)$ Mitochondria,chloroplasts and peroxisomes are not considered as part of endomembrane system.
Of the above statements:

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

Which of the following biomolecules acts as specific catalysts in biological reactions?

$(p \to q) \leftrightarrow (q \vee \sim p)$ is

The slopes of the focal chords of the parabola $y^2=32x$,which are tangents to the circle $x^2+y^2=4$,are