When glucose reacts with bromine water,the main product is

Which one of the following is correctly matched?

Match the following columns and select the correct option:

Column-$I$	Column-$II$
$(a)$ Floating ribs	$(i)$ Located between $2^{nd}$ and $7^{th}$ ribs
$(b)$ Acromion process	$(ii)$ Head of humerus
$(c)$ Scapula	$(iii)$ Clavicle articulation
$(d)$ Glenoid cavity	$(iv)$ Do not connect with the sternum

$(a)\quad(b)\quad(c)\quad(d)$

The angle between the straight lines $x^2+4xy+y^2=0$ is....... (in $^{\circ}$)

Particles of masses $m, 2m, 3m, \dots, nm$ grams are placed on the same line at distances $l, 2l, 3l, \dots, nl$ cm from a fixed point. The distance of the centre of mass of the particles from the fixed point in centimetres is:

The angle between the lines represented by $(\sin^2 \alpha) y^2 - 2xy(\cos^2 \alpha) + (\cos^2 \alpha - 1) x^2 = 0$ is