Match the columns Column I Column II (a) Biodegradable (p) polyacrylonitrie (b) Synthetic (q) PHBV (c) Natural (r) dacron (d) Polyester (s) Rubber
a-q; b-p; c-s; d-r
a-q; b-p; c-r; d-s
a-p; b-q; c-s; d-r
a-q; b-r; c-s; d-p
The correct answer is option (A)

Let \( \alpha = \dfrac{-1 + i\sqrt{3}}{2} \) and \( \beta = \dfrac{-1 - i\sqrt{3}}{2} \), where \( i = \sqrt{-1} \). If
\[ (7 - 7\alpha + 9\beta)^{20} + (9 + 7\alpha - 7\beta)^{20} + (-7 + 9\alpha + 7\beta)^{20} + (14 + 7\alpha + 7\beta)^{20} = m^{10}, \] then the value of \( m \) is ___________.
Neoprene is formed from chloroprene. It is prepared by free radical polymerisation. The monomer of neoprene is chloroprene. It is used for preparing gaskets, conveyor belts etc.