Which of the following is a part of the pectoral girdle?

When carbon monoxide is passed over solid caustic soda heated to $200^\circ C$,it forms

$A$ beaker full of hot water is kept in a room. If it cools from $80\,^{\circ}C$ to $75\,^{\circ}C$ in $t_1$ minutes,from $75\,^{\circ}C$ to $70\,^{\circ}C$ in $t_2$ minutes,and from $70\,^{\circ}C$ to $65\,^{\circ}C$ in $t_3$ minutes,then:

$A$ nucleus of uranium decays at rest into nuclei of thorium and helium. Then:

The bob of a simple pendulum is hanging vertically down from a fixed identical bob by means of a string of length $l$. If both bobs are charged with a charge $q$ each,what is the time period of the pendulum? (Ignore the radii of the bobs.)

Which one of the following characters is not typical of the class Mammalia?